Aluminium silicon carbide (AlSiC) metal-matrix composite AlSiC
Composite of aluminium alloy 356 (matrix) and silicon carbide particles (reinforcement) · CAS 409-21-2 (silicon carbide reinforcement, PubChem CID 9863; the composite has no CAS number in the sources read)
Also known as AlSiC-9, AlSiC-10, AlSiC-12
Aluminium silicon carbide (AlSiC) is a metal-matrix composite of an aluminium alloy (alloy 356 in the CPS Technologies grades) reinforced with silicon carbide (SiC) particles.
Evidence level
2 of 5
Lab-measured
- 0Predicted only. No one has made it, or no measurement exists.
- 1Calculated. Only calculated or predicted values from sources.
- 2Lab-measured. Measured properties with their conditions stated.
- 3Space-relevant tests. Measured in conditions relevant to space, such as vacuum or atomic oxygen.
- 4Ground-qualified. Qualified for an application on the ground.
- 5Flown or field-proven. Flight or field results exist.
Carry heat
190 W/mK typical, AlSiC-9, 25 °C
Match a chip's expansion
8.00 ppm/°C, AlSiC-9, 30-100 °C
Stay light
2.89 to 3.01 g/cm3
Form complex parts
Near net shape
Recipe, share of the weight
- Al not statedAluminium alloy 356 (matrix)
- SiC not statedSilicon carbide (reinforcement)
Best for
Matching the thermal expansion of silicon, gallium arsenide or ceramic chips while spreading heat in power electronics, in a material of 2.89 to 3.01 g/cm3 (AlSiC-12 to AlSiC-9)
Weakest at
Ductility: 11.3 MPa/m2 fracture toughness and 0.295 percent elongation at rupture for AlSiC-9 (CPS 2025), and silicon carbide dust that PubChem lists with a cancer-by-inhalation hazard statement
Risk at a glance
- People Low. Mixed notifications
- If it fails Moderate. Brittle fracture under high load
- Corrosion No data. No corrosion data recorded
Quick facts: AlSiC
| Property | Value | Basis |
|---|---|---|
| Density | 2.8 to 3.01 g/cm³ | 6 sourced values across conditions |
| Young's modulus | 167 to 188 GPa | 2 sourced values across conditions |
| Thermal conductivity | 170 to 200 W/(m·K) | 7 sourced values across conditions |
| Thermal expansion (CTE) | 13 to 15 ppm/K | 2 sourced values across conditions |
| Specific heat | 741 to 808 J/(kg·K) | 2 sourced values across conditions |
| Electrical resistivity | 2.1e-7 Ω·m | 2 sourced values across conditions |
What is the density of Aluminium silicon carbide (AlSiC) metal-matrix composite?
Aluminium silicon carbide (AlSiC) metal-matrix composite has a density of 2.8 to 3.01 g/cm³. The range covers 6 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What is the thermal conductivity of Aluminium silicon carbide (AlSiC) metal-matrix composite?
Aluminium silicon carbide (AlSiC) metal-matrix composite has a thermal conductivity of 170 to 200 W/(m·K). The range covers 7 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What is the coefficient of thermal expansion of Aluminium silicon carbide (AlSiC) metal-matrix composite?
Aluminium silicon carbide (AlSiC) metal-matrix composite has a coefficient of thermal expansion of 13 to 15 ppm/K. The range covers 2 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What is the Young's modulus of Aluminium silicon carbide (AlSiC) metal-matrix composite?
Aluminium silicon carbide (AlSiC) metal-matrix composite has a Young's modulus of 167 to 188 GPa. The range covers 2 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What are the other names and codes for Aluminium silicon carbide (AlSiC) metal-matrix composite?
Aluminium silicon carbide (AlSiC) metal-matrix composite is also written as AlSiC-9, AlSiC-10, AlSiC-12. Each code is printed in the source listed beside it in the designations table.
What is Aluminium silicon carbide (AlSiC) metal-matrix composite used for?
Uses recorded in the sources include Power semiconductor base plates and flip-chip lids; Pin-fin and single-piece coolers for power electronics; Hermetic packages for military, aerospace and communications systems.
Why it exists
AlSiC is used where a part must match the thermal expansion of a chip and still carry heat away while staying light. CPS Technologies prints a thermal conductivity of 190 W/mK typical at 25 °C for AlSiC-9, with a minimum of 180 W/mK, and a coefficient of thermal expansion of 8.00 ppm/°C from 30 to 100 °C. Wikipedia says the thermal expansion can be tuned to match silicon, gallium arsenide and several ceramics, and that AlSiC is mainly used in microelectronics as a substrate for power semiconductors.
Recipe
Composite of aluminium alloy 356 (matrix) and silicon carbide particles (reinforcement); AlSiC-9 is 37% vol aluminium alloy 356 and 63% vol silicon carbide (CPS 2025 slide)
AlSiC is a metal-matrix composite, not a single alloy. CPS Technologies describes a two-step process: quickset injection moulding makes a porous ceramic preform that matches the final part geometry, then pressurised melt infiltration fills the preform porosity with aluminium, giving a fully dense part with the same shape (CPS 2025 slide). Wikipedia describes the same route as injection moulding of a silicon carbide binder slurry, firing to remove the binder, then infiltration under pressure with molten aluminium.
| Ingredient | Share of the weight | What it does |
|---|---|---|
| Aluminium alloy 356 (matrix) Al | not stated | Metal matrix that is infiltrated into the SiC preform. Wikipedia says the aluminium matrix has many dislocations, which give the material its strength. |
| Silicon carbide (reinforcement) SiC | not stated | Particle reinforcement that sets the thermal expansion. |
Weight shares are as printed in the sources.
What it can do
Carry heat
190 W/mK typical, AlSiC-9, 25 °C
measured
CPS Technologies prints 190 W/mK typical and 180 W/mK minimum at 25 °C for AlSiC-9, and 180 W/mK typical and 170 W/mK minimum for AlSiC-12. Wikipedia gives 190-200 W/m K for AlSiC-9 and AlSiC-10, and 170-180 W/m K for AlSiC-12, without a temperature.
Match a chip's expansion
8.00 ppm/°C, AlSiC-9, 30-100 °C
measured
CPS prints 8.00 ppm/°C from 30 to 100 °C and 8.75 ppm/°C from 30 to 200 °C for AlSiC-9. The same slide prints 10.90 ppm/°C and 11.70 ppm/°C for AlSiC-12 over the same ranges.
Stay light
2.89 to 3.01 g/cm3
measured
CPS prints 3.01 g/cm3 for AlSiC-9 and 2.89 g/cm3 for AlSiC-12. CPS's hermetic packaging datasheet says AlSiC is 40-60% lighter than CuMo and CuW.
Form complex parts
Near net shape
Ferrotec lists near net shape processing as a benefit, and CPS says net-shape manufacturing removes costly machining. The sources do not give a tolerance.
How it compares
CuMo and CuW are the heat-spreader alternatives AlSiC replaces. CPS's hermetic packaging datasheet says AlSiC is 40-60% lighter than CuMo and CuW and lower in cost. Wikipedia says AlSiC weighs about one-third as much as copper. Inside the family, the Ferrotec table shows the trade-off: going from Al75/SiC25 to Al60/SiC40 lowers the printed coefficient of thermal expansion from 15 to 13 (1/°C×10-6) and raises the printed density from 2.8 to 2.9 g/cm3. The sources give no like-for-like figure against a bare aluminium alloy, so none is stated here.
The same measurements for each material, so you can compare them. Each row names the key condition under the value; the full conditions and methods are in the numbered notes under Technical details.
| Measurement | AlSiC |
|---|---|
| Thermal behavior and safety | |
| Thermal conductivity, AlSiC-9, typical (CPS 2025)Value printed in a manufacturer product slide | 190 W/mK3 |
| Thermal conductivity, AlSiC-9, minimum (CPS 2025)Value printed in a manufacturer product slide | 180 W/mK4 |
| Thermal conductivity, AlSiC-12, typical (CPS 2025)Value printed in a manufacturer product slide | 180 W/mK5 |
| Thermal conductivity, AlSiC-12, minimum (CPS 2025)Value printed in a manufacturer product slide | 170 W/mK6 |
| Specific heat, AlSiC-9 (CPS 2025) | 0.741 J/gK13 |
| Specific heat, AlSiC-12 (CPS 2025) | 0.808 J/gK14 |
| Thermal conductivity, AlSiC-10 (Wikipedia) | 190 W/m K31 |
| Thermal conductivity, AlSiC-9 (Wikipedia) | 190 W/m K32 |
| Thermal conductivity, AlSiC-12 (Wikipedia) | 170 W/m K33 |
| Physical and electrical | |
| Density, AlSiC-9 (CPS 2025)Value printed in a manufacturer product slide | 3.01 g/cm³1 |
| Density, AlSiC-12 (CPS 2025)Value printed in a manufacturer product slide | 2.89 g/cm³2 |
| Electrical resistance, AlSiC-9, printed in microohm-cm (CPS 2025)Value printed in a manufacturer product slide | 20.7 µOhm-cm23 |
| Electrical resistance, AlSiC-12, printed in microohm-cm (CPS 2025)Value printed in a manufacturer product slide | 20.7 µOhm-cm24 |
| Density, Al75/SiC25 (Ferrotec)Value printed on a manufacturer product web page | 2.8 g/cm³25 |
| Density, Al70/SiC30 (Ferrotec)Value printed on a manufacturer product web page | 2.8 g/cm³26 |
| Density, Al60/SiC40 (Ferrotec)Value printed on a manufacturer product web page | 2.9 g/cm³27 |
| Density, AlSiC-10 at 25 °C (Wikipedia) | 2.96 g/cm³30 |
| Other measurements | |
| Coefficient of thermal expansion, AlSiC-9, 30-100 °C (CPS 2025)Value printed in a manufacturer product slide | 8 ppm/°C7 |
| Coefficient of thermal expansion, AlSiC-9, 30-150 °C (CPS 2025)Value printed in a manufacturer product slide | 8.37 ppm/°C8 |
| Coefficient of thermal expansion, AlSiC-9, 30-200 °C (CPS 2025)Value printed in a manufacturer product slide | 8.75 ppm/°C9 |
| Coefficient of thermal expansion, AlSiC-12, 30-100 °C (CPS 2025)Value printed in a manufacturer product slide | 10.9 ppm/°C10 |
| Coefficient of thermal expansion, AlSiC-12, 30-150 °C (CPS 2025)Value printed in a manufacturer product slide | 11.2 ppm/°C11 |
| Coefficient of thermal expansion, AlSiC-12, 30-200 °C (CPS 2025)Value printed in a manufacturer product slide | 11.7 ppm/°C12 |
| Young's modulus, AlSiC-9 (CPS 2025)Value printed in a manufacturer product slide | 188 GPa15 |
| Young's modulus, AlSiC-12 (CPS 2025)Value printed in a manufacturer product slide | 167 GPa16 |
| Shear modulus, AlSiC-9 (CPS 2025)Value printed in a manufacturer product slide | 76 GPa17 |
| Shear modulus, AlSiC-12 (CPS 2025)Value printed in a manufacturer product slide | 69 GPa18 |
| Four-point bend strength, AlSiC-9 (CPS 2025) | 488 MPa19 |
| Four-point bend strength, AlSiC-12 (CPS 2025) | 471 MPa20 |
| Fracture toughness, AlSiC-9 (CPS 2025)Value printed in a manufacturer product slide | 11.3 MPa/m221 |
| Percent elongation at rupture, AlSiC-9 (CPS 2025)Value printed in a manufacturer product slide | 0.295 %22 |
| Coefficient of thermal expansion, Al75/SiC25 (Ferrotec)Value printed on a manufacturer product web page | 15 ppm/°C28 |
| Coefficient of thermal expansion, Al60/SiC40 (Ferrotec)Value printed on a manufacturer product web page | 13 ppm/°C29 |
Why choose it, and why not
Good for
- Matching a chip's expansion while removing heat: AlSiC-9 has 8.00 ppm/°C from 30 to 100 °C and 190 W/mK typical at 25 °C (CPS 2025).
- Light heat spreaders and coolers: 3.01 g/cm3 for AlSiC-9, and a single-piece cooler with integrated channels (CPS 2025).
- Hermetic housings: CPS says its hermetic packages use a two-step sealing process (CPS hermetic packaging datasheet).
Watch out for
- Brittle at the limit: AlSiC-9 prints 11.3 MPa/m2 fracture toughness and 0.295 percent elongation at rupture (CPS 2025).
- Grade choice changes the match: AlSiC-9 is 8.75 ppm/°C and AlSiC-12 is 11.70 ppm/°C at 30-200 °C (CPS 2025).
- Silicon carbide dust: PubChem lists H350i for silicon carbide, and quotes IARC Vol. 111 for fibrous silicon carbide (Group 2B) and whiskers (Group 2A).
- Coating data are thin: Wikipedia says nickel or nickel-gold plating is possible, but the sources read give no corrosion or galvanic test data.
AlSiC is a light, low-expansion metal-matrix composite for power electronics and hermetic packages. The CPS 2025 slide gives the grade-level values, with 190 W/mK typical and 8.00 ppm/°C for AlSiC-9. The space uses are vendor statements from CPS's company history, and no NASA or ESA material-selection document was found in this run. Corrosion data, silicon carbide supply and fracture data for the other grades are gaps.
Technical details
For scientists and researchers. Everything above comes from the record below: every number with its method, its conditions and its source.
Other names and standards
The same grade under other systems, as datasheets and standards print them. Each code was checked against the page it comes from.
| System | Codes |
|---|---|
| Trade name | AlSiC-9, AlSiC-10, AlSiC-12 |
Notes
The method, full conditions and any caveat for the numbered rows above.
| # | Measurement | Method | Conditions | Caveat |
|---|---|---|---|---|
| 1 | Density, AlSiC-9 (CPS 2025) | — | grade AlSiC-9composition 37% vol aluminium alloy 356, 63% vol SiCtemperature not stated on the slideprinted 3.01 | — |
| 2 | Density, AlSiC-12 (CPS 2025) | — | grade AlSiC-12composition 63% vol aluminium alloy 356, 37% vol SiCtemperature not stated on the slideprinted 2.89 | — |
| 3 | Thermal conductivity, AlSiC-9, typical (CPS 2025) | — | grade AlSiC-9temperature 25 °Cbasis typicalprinted 190 typical | — |
| 4 | Thermal conductivity, AlSiC-9, minimum (CPS 2025) | — | grade AlSiC-9temperature 25 °Cbasis minimumprinted 180 min | — |
| 5 | Thermal conductivity, AlSiC-12, typical (CPS 2025) | — | grade AlSiC-12temperature 25 °Cbasis typicalprinted 180 typical | — |
| 6 | Thermal conductivity, AlSiC-12, minimum (CPS 2025) | — | grade AlSiC-12temperature 25 °Cbasis minimumprinted 170 min | — |
| 7 | Coefficient of thermal expansion, AlSiC-9, 30-100 °C (CPS 2025) | — | grade AlSiC-9temperature 30-100 °Cprinted 8.00 | — |
| 8 | Coefficient of thermal expansion, AlSiC-9, 30-150 °C (CPS 2025) | — | grade AlSiC-9temperature 30-150 °Cprinted 8.37 | — |
| 9 | Coefficient of thermal expansion, AlSiC-9, 30-200 °C (CPS 2025) | — | grade AlSiC-9temperature 30-200 °Cprinted 8.75 | — |
| 10 | Coefficient of thermal expansion, AlSiC-12, 30-100 °C (CPS 2025) | — | grade AlSiC-12temperature 30-100 °Cprinted 10.90 | — |
| 11 | Coefficient of thermal expansion, AlSiC-12, 30-150 °C (CPS 2025) | — | grade AlSiC-12temperature 30-150 °Cprinted 11.20 | — |
| 12 | Coefficient of thermal expansion, AlSiC-12, 30-200 °C (CPS 2025) | — | grade AlSiC-12temperature 30-200 °Cprinted 11.70 | — |
| 13 | Specific heat, AlSiC-9 (CPS 2025) | Value printed in a manufacturer product slide; unit printed as J/gK | grade AlSiC-9temperature 25 °Cprinted 0.741 | — |
| 14 | Specific heat, AlSiC-12 (CPS 2025) | Value printed in a manufacturer product slide; unit printed as J/gK | grade AlSiC-12temperature 25 °Cprinted 0.808 | — |
| 15 | Young's modulus, AlSiC-9 (CPS 2025) | — | grade AlSiC-9temperature not stated on the slideprinted 188 | — |
| 16 | Young's modulus, AlSiC-12 (CPS 2025) | — | grade AlSiC-12temperature not stated on the slideprinted 167 | — |
| 17 | Shear modulus, AlSiC-9 (CPS 2025) | — | grade AlSiC-9temperature not stated on the slideprinted 76 | — |
| 18 | Shear modulus, AlSiC-12 (CPS 2025) | — | grade AlSiC-12temperature not stated on the slideprinted 69 | — |
| 19 | Four-point bend strength, AlSiC-9 (CPS 2025) | Value printed in a manufacturer product slide; the slide does not use the word flexural | grade AlSiC-9test four-point bend, printed as A-Bar 4-pt Bend Strengthtemperature not stated on the slideprinted 488 | — |
| 20 | Four-point bend strength, AlSiC-12 (CPS 2025) | Value printed in a manufacturer product slide; the slide does not use the word flexural | grade AlSiC-12test four-point bend, printed as A-Bar 4-pt Bend Strengthtemperature not stated on the slideprinted 471 | — |
| 21 | Fracture toughness, AlSiC-9 (CPS 2025) | — | grade AlSiC-9temperature not stated on the slideprinted 11.3note name is not in the canonical list; see gaps | — |
| 22 | Percent elongation at rupture, AlSiC-9 (CPS 2025) | — | grade AlSiC-9temperature not stated on the slideprinted 0.295unit in source row name Percent Elongation at Rupture, no unit printed beyond the name | — |
| 23 | Electrical resistance, AlSiC-9, printed in microohm-cm (CPS 2025) | — | grade AlSiC-9temperature not stated on the slideprinted 20.7note printed as Electrical Resistance; see gaps | — |
| 24 | Electrical resistance, AlSiC-12, printed in microohm-cm (CPS 2025) | — | grade AlSiC-12temperature not stated on the slideprinted 20.7note printed as Electrical Resistance; see gaps | — |
| 25 | Density, Al75/SiC25 (Ferrotec) | — | composition Al 75 vol%, SiC 25 vol%temperature not stated on the pageprinted 2.8 | — |
| 26 | Density, Al70/SiC30 (Ferrotec) | — | composition Al 70 vol%, SiC 30 vol%temperature not stated on the pageprinted 2.8 | — |
| 27 | Density, Al60/SiC40 (Ferrotec) | — | composition Al 60 vol%, SiC 40 vol%temperature not stated on the pageprinted 2.9 | — |
| 28 | Coefficient of thermal expansion, Al75/SiC25 (Ferrotec) | — | composition Al 75 vol%, SiC 25 vol%temperature not stated on the pageprinted 15unit in source 1/°C×10-6 | — |
| 29 | Coefficient of thermal expansion, Al60/SiC40 (Ferrotec) | — | composition Al 60 vol%, SiC 40 vol%temperature not stated on the pageprinted 13unit in source 1/°C×10-6 | — |
| 30 | Density, AlSiC-10 at 25 °C (Wikipedia) | Value printed in a Wikipedia article that cites manufacturer data | grade AlSiC-10composition 45 vol% A 356.2 aluminium alloy, 55 vol% SiCtemperature 25 °Cprinted 2.96 | — |
| 31 | Thermal conductivity, AlSiC-10 (Wikipedia) | Range printed in a Wikipedia article that cites manufacturer data | grade AlSiC-10temperature not stated on the pageprinted 190-200 | — |
| 32 | Thermal conductivity, AlSiC-9 (Wikipedia) | Range printed in a Wikipedia article that cites manufacturer data | grade AlSiC-9temperature not stated on the pageprinted 190-200 | — |
| 33 | Thermal conductivity, AlSiC-12 (Wikipedia) | Range printed in a Wikipedia article that cites manufacturer data | grade AlSiC-12temperature not stated on the pageprinted 170-180 | — |
Risks and side effects
Hazards to people, what happens when a cell overheats, and how the material is handled and stored.
For people
The silicon carbide hazard depends on the form of the dust, and the sources differ on how serious it is.
- Silicon carbide as a substance
- PubChem reports H350i, May cause cancer by inhalation, with signal word Danger. The ECHA aggregation says 740 of 1053 company reports did not meet GHS hazard criteria.
- Fibre versus particle
- IARC Vol. 111 lists fibrous silicon carbide as Group 2B and whiskers as Group 2A, while ACGIH says nonfibrous particles have low to very low toxic effects on lung tissue.
- Irritation
- The NIOSH Pocket Guide excerpt in PubChem lists irritation of the eyes, skin and upper respiratory system, and cough.
Test details
The original wording and numbers from the sources, for readers who want them.
Failure risks
| Failure | Trigger and consequence |
|---|---|
| Brittle fracture under high loadmoderate severity | Stress approaching the four-point bend strength of 488 MPa for AlSiC-9The 2025 CPS slide prints a fracture toughness of 11.3 MPa/m2 and a percent elongation at rupture of 0.295 for AlSiC-9. The slide gives no further failure data. |
| Thermal expansion mismatch from the wrong grademoderate severity | Attaching AlSiC to a chip or substrate whose expansion differs from the grade chosenCPS prints 8.00 ppm/°C for AlSiC-9 and 10.90 ppm/°C for AlSiC-12 at 30-100 °C, so the grade sets the match. The sources read give no stress or fatigue data for a mismatched joint. |
Side effects on surrounding parts
| Affects | Effect |
|---|---|
| Workers who cut, grind or drill AlSiC parts | Silicon carbide dust from machining is the handling concern named in the sources; the CPS sheet itself names no side effect of the composite. |
Handling and storage
- Name the grade on every drawing: AlSiC-9, AlSiC-10 and AlSiC-12 differ in thermal expansion, conductivity and density, per the CPS 2025 slide and Wikipedia.
- Control dust when cutting, grinding or drilling AlSiC. The IARC concern is fibrous silicon carbide, and PubChem quotes NIOSH for eye, skin and airway irritation from the silicon carbide dust.
- Surface finish: Wikipedia says AlSiC can be plated with nickel or nickel-gold, or coated with other metals by thermal spraying. The sources read give no plating or corrosion test data.
- Plating compatibility: CPS says its AlSiC pin fin coolers support standard solderable plating schemes and Copper Cold Gas Spray. That sheet gives no corrosion result for any plated finish.
Supply and geography
How common the raw materials are and where they come from.
Primary aluminium, the matrix metal
- Recycling
- USGS 2026: aluminum recovered from purchased scrap in the United States was about 3.6 million tons in 2025, of which about 56% came from new scrap and 44% from old scrap.
AlSiC composites (manufacturers named in the sources)
Documents
Datasheets, safety data sheets, papers and standards you can open.
| Document | Type | Year |
|---|---|---|
| Wikipedia: AlSiC | database | |
| Al-SiC Metal Matrix Composite Ceramic Material (Ferrotec Advanced Ceramics) | datasheet | |
| CPS AlSiC Composites, 2025 product slide | datasheet | 2025 |
| CPS AlSiC Hermetic Packaging datasheet | datasheet | |
| Mineral Commodity Summaries 2026: Aluminum (U.S. Geological Survey) | report | 2026 |
| PubChem: Silicon carbide, CID 9863 | database | |
| AlSiC Pin Fin Coolers, CPS Technologies product sheet | datasheet |
Full record
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spore: profile
id: alsic
spore_version: 0.2
family: aluminium-silicon-carbide
name: Aluminium silicon carbide (AlSiC) metal-matrix composite
abbreviation: AlSiC
role: thermal-management substrate, heat spreader and hermetic housing
category: composites
type: metal-matrix
summary: Aluminium silicon carbide (AlSiC) is a metal-matrix composite of an aluminium alloy (alloy 356 in the CPS Technologies grades) reinforced with silicon carbide (SiC) particles. CPS Technologies prints a density of 3.01 g/cm3 and a thermal conductivity of 190 W/mK typical at 25 °C for the AlSiC-9 grade, which is 37% vol aluminium alloy and 63% vol silicon carbide. The same grade has a coefficient of thermal expansion of 8.00 ppm/°C from 30 to 100 °C, and Wikipedia says the expansion can be tuned to match silicon, gallium arsenide and several ceramics.
best_for: Matching the thermal expansion of silicon, gallium arsenide or ceramic chips while spreading heat in power electronics, in a material of 2.89 to 3.01 g/cm3 (AlSiC-12 to AlSiC-9)
weakest_at: 'Ductility: 11.3 MPa/m2 fracture toughness and 0.295 percent elongation at rupture for AlSiC-9 (CPS 2025), and silicon carbide dust that PubChem lists with a cancer-by-inhalation hazard statement'
identity:
formula: Composite of aluminium alloy 356 (matrix) and silicon carbide particles (reinforcement); AlSiC-9 is 37% vol aluminium alloy 356 and 63% vol silicon carbide (CPS 2025 slide)
cas: 409-21-2 (silicon carbide reinforcement, PubChem CID 9863; the composite has no CAS number in the sources read)
source: cps-alsic-2025
where: Select Material Properties table, rows Aluminum Alloy 356 and Silicon Carbide
designations:
- system: Trade name
code: AlSiC-9
source: cps-alsic-2025
where: Select Material Properties table, column AlSiC-9
- system: Trade name
code: AlSiC-10
source: wikipedia-alsic
where: Grades list, AlSiC-10 entry
- system: Trade name
code: AlSiC-12
source: cps-alsic-2025
where: Select Material Properties table, column AlSiC-12
tags:
environments: []
stresses: []
applications:
- electronics-and-chips
- thermal-control
- optics-and-cameras
- rovers-and-surface-systems
properties:
- benchmark: density
label: Density, AlSiC-9 (CPS 2025)
value: 3.01
unit: g/cm3
scope: material
conditions:
grade: AlSiC-9
composition: 37% vol aluminium alloy 356, 63% vol SiC
temperature: not stated on the slide
printed: '3.01'
method: Value printed in a manufacturer product slide
status: ground
source: cps-alsic-2025
where: Select Material Properties table, Density (g/cm3) row, AlSiC-9 column
- benchmark: density
label: Density, AlSiC-12 (CPS 2025)
value: 2.89
unit: g/cm3
scope: material
conditions:
grade: AlSiC-12
composition: 63% vol aluminium alloy 356, 37% vol SiC
temperature: not stated on the slide
printed: '2.89'
method: Value printed in a manufacturer product slide
status: ground
source: cps-alsic-2025
where: Select Material Properties table, Density (g/cm3) row, AlSiC-12 column
- benchmark: thermal_conductivity
label: Thermal conductivity, AlSiC-9, typical (CPS 2025)
value: 190
unit: W/mK
scope: material
conditions:
grade: AlSiC-9
temperature: 25 °C
basis: typical
printed: 190 typical
method: Value printed in a manufacturer product slide
status: ground
source: cps-alsic-2025
where: Select Material Properties table, Thermal Conductivity @25°C (W/mK) row, AlSiC-9 column, typical value
- benchmark: thermal_conductivity
label: Thermal conductivity, AlSiC-9, minimum (CPS 2025)
value: 180
unit: W/mK
scope: material
conditions:
grade: AlSiC-9
temperature: 25 °C
basis: minimum
printed: 180 min
method: Value printed in a manufacturer product slide
status: ground
source: cps-alsic-2025
where: Select Material Properties table, Thermal Conductivity @25°C (W/mK) row, AlSiC-9 column, minimum value
- benchmark: thermal_conductivity
label: Thermal conductivity, AlSiC-12, typical (CPS 2025)
value: 180
unit: W/mK
scope: material
conditions:
grade: AlSiC-12
temperature: 25 °C
basis: typical
printed: 180 typical
method: Value printed in a manufacturer product slide
status: ground
source: cps-alsic-2025
where: Select Material Properties table, Thermal Conductivity @25°C (W/mK) row, AlSiC-12 column, typical value
- benchmark: thermal_conductivity
label: Thermal conductivity, AlSiC-12, minimum (CPS 2025)
value: 170
unit: W/mK
scope: material
conditions:
grade: AlSiC-12
temperature: 25 °C
basis: minimum
printed: 170 min
method: Value printed in a manufacturer product slide
status: ground
source: cps-alsic-2025
where: Select Material Properties table, Thermal Conductivity @25°C (W/mK) row, AlSiC-12 column, minimum value
- benchmark: cte
label: Coefficient of thermal expansion, AlSiC-9, 30-100 °C (CPS 2025)
value: 8
unit: ppm/°C
scope: material
conditions:
grade: AlSiC-9
temperature: 30-100 °C
printed: '8.00'
method: Value printed in a manufacturer product slide
status: ground
source: cps-alsic-2025
where: Select Material Properties table, Thermal Expansion (CTE) row, 30-100°C line, AlSiC-9 column
- benchmark: cte
label: Coefficient of thermal expansion, AlSiC-9, 30-150 °C (CPS 2025)
value: 8.37
unit: ppm/°C
scope: material
conditions:
grade: AlSiC-9
temperature: 30-150 °C
printed: '8.37'
method: Value printed in a manufacturer product slide
status: ground
source: cps-alsic-2025
where: Select Material Properties table, Thermal Expansion (CTE) row, 30-150°C line, AlSiC-9 column
- benchmark: cte
label: Coefficient of thermal expansion, AlSiC-9, 30-200 °C (CPS 2025)
value: 8.75
unit: ppm/°C
scope: material
conditions:
grade: AlSiC-9
temperature: 30-200 °C
printed: '8.75'
method: Value printed in a manufacturer product slide
status: ground
source: cps-alsic-2025
where: Select Material Properties table, Thermal Expansion (CTE) row, 30-200°C line, AlSiC-9 column
- benchmark: cte
label: Coefficient of thermal expansion, AlSiC-12, 30-100 °C (CPS 2025)
value: 10.9
unit: ppm/°C
scope: material
conditions:
grade: AlSiC-12
temperature: 30-100 °C
printed: '10.90'
method: Value printed in a manufacturer product slide
status: ground
source: cps-alsic-2025
where: Select Material Properties table, Thermal Expansion (CTE) row, 30-100°C line, AlSiC-12 column
- benchmark: cte
label: Coefficient of thermal expansion, AlSiC-12, 30-150 °C (CPS 2025)
value: 11.2
unit: ppm/°C
scope: material
conditions:
grade: AlSiC-12
temperature: 30-150 °C
printed: '11.20'
method: Value printed in a manufacturer product slide
status: ground
source: cps-alsic-2025
where: Select Material Properties table, Thermal Expansion (CTE) row, 30-150°C line, AlSiC-12 column
- benchmark: cte
label: Coefficient of thermal expansion, AlSiC-12, 30-200 °C (CPS 2025)
value: 11.7
unit: ppm/°C
scope: material
conditions:
grade: AlSiC-12
temperature: 30-200 °C
printed: '11.70'
method: Value printed in a manufacturer product slide
status: ground
source: cps-alsic-2025
where: Select Material Properties table, Thermal Expansion (CTE) row, 30-200°C line, AlSiC-12 column
- benchmark: specific_heat
label: Specific heat, AlSiC-9 (CPS 2025)
value: 0.741
unit: J/gK
scope: material
conditions:
grade: AlSiC-9
temperature: 25 °C
printed: '0.741'
method: Value printed in a manufacturer product slide; unit printed as J/gK
status: ground
source: cps-alsic-2025
where: Select Material Properties table, Specific Heat @25°C (J/gK) row, AlSiC-9 column
- benchmark: specific_heat
label: Specific heat, AlSiC-12 (CPS 2025)
value: 0.808
unit: J/gK
scope: material
conditions:
grade: AlSiC-12
temperature: 25 °C
printed: '0.808'
method: Value printed in a manufacturer product slide; unit printed as J/gK
status: ground
source: cps-alsic-2025
where: Select Material Properties table, Specific Heat @25°C (J/gK) row, AlSiC-12 column
- benchmark: elastic_modulus
label: Young's modulus, AlSiC-9 (CPS 2025)
value: 188
unit: GPa
scope: material
conditions:
grade: AlSiC-9
temperature: not stated on the slide
printed: '188'
method: Value printed in a manufacturer product slide
status: ground
source: cps-alsic-2025
where: Select Material Properties table, Young's Modulus (GPa) row, AlSiC-9 column
- benchmark: elastic_modulus
label: Young's modulus, AlSiC-12 (CPS 2025)
value: 167
unit: GPa
scope: material
conditions:
grade: AlSiC-12
temperature: not stated on the slide
printed: '167'
method: Value printed in a manufacturer product slide
status: ground
source: cps-alsic-2025
where: Select Material Properties table, Young's Modulus (GPa) row, AlSiC-12 column
- benchmark: shear_modulus
label: Shear modulus, AlSiC-9 (CPS 2025)
value: 76
unit: GPa
scope: material
conditions:
grade: AlSiC-9
temperature: not stated on the slide
printed: '76'
method: Value printed in a manufacturer product slide
status: ground
source: cps-alsic-2025
where: Select Material Properties table, Shear Modulus (GPa) row, AlSiC-9 column
- benchmark: shear_modulus
label: Shear modulus, AlSiC-12 (CPS 2025)
value: 69
unit: GPa
scope: material
conditions:
grade: AlSiC-12
temperature: not stated on the slide
printed: '69'
method: Value printed in a manufacturer product slide
status: ground
source: cps-alsic-2025
where: Select Material Properties table, Shear Modulus (GPa) row, AlSiC-12 column
- benchmark: flexural_strength
label: Four-point bend strength, AlSiC-9 (CPS 2025)
value: 488
unit: MPa
scope: material
conditions:
grade: AlSiC-9
test: four-point bend, printed as A-Bar 4-pt Bend Strength
temperature: not stated on the slide
printed: '488'
method: Value printed in a manufacturer product slide; the slide does not use the word flexural
status: ground
source: cps-alsic-2025
where: Select Material Properties table, A-Bar 4-pt Bend Strength (MPa) row, AlSiC-9 column
- benchmark: flexural_strength
label: Four-point bend strength, AlSiC-12 (CPS 2025)
value: 471
unit: MPa
scope: material
conditions:
grade: AlSiC-12
test: four-point bend, printed as A-Bar 4-pt Bend Strength
temperature: not stated on the slide
printed: '471'
method: Value printed in a manufacturer product slide; the slide does not use the word flexural
status: ground
source: cps-alsic-2025
where: Select Material Properties table, A-Bar 4-pt Bend Strength (MPa) row, AlSiC-12 column
- benchmark: fracture_toughness
label: Fracture toughness, AlSiC-9 (CPS 2025)
value: 11.3
unit: MPa/m2
scope: material
conditions:
grade: AlSiC-9
temperature: not stated on the slide
printed: '11.3'
note: name is not in the canonical list; see gaps
method: Value printed in a manufacturer product slide
status: ground
source: cps-alsic-2025
where: Select Material Properties table, Fracture Toughness (MPa/m2) row, AlSiC-9 column
- benchmark: elongation
label: Percent elongation at rupture, AlSiC-9 (CPS 2025)
value: 0.295
unit: '%'
scope: material
conditions:
grade: AlSiC-9
temperature: not stated on the slide
printed: '0.295'
unit_in_source: row name Percent Elongation at Rupture, no unit printed beyond the name
method: Value printed in a manufacturer product slide
status: ground
source: cps-alsic-2025
where: Select Material Properties table, Percent Elongation at Rupture row, AlSiC-9 column
- benchmark: electrical_resistivity
label: Electrical resistance, AlSiC-9, printed in microohm-cm (CPS 2025)
value: 20.7
unit: µOhm-cm
scope: material
conditions:
grade: AlSiC-9
temperature: not stated on the slide
printed: '20.7'
note: printed as Electrical Resistance; see gaps
method: Value printed in a manufacturer product slide
status: ground
source: cps-alsic-2025
where: Select Material Properties table, Electrical Resistance (µOhm-cm) row, AlSiC-9 column
- benchmark: electrical_resistivity
label: Electrical resistance, AlSiC-12, printed in microohm-cm (CPS 2025)
value: 20.7
unit: µOhm-cm
scope: material
conditions:
grade: AlSiC-12
temperature: not stated on the slide
printed: '20.7'
note: printed as Electrical Resistance; see gaps
method: Value printed in a manufacturer product slide
status: ground
source: cps-alsic-2025
where: Select Material Properties table, Electrical Resistance (µOhm-cm) row, AlSiC-12 column
- benchmark: density
label: Density, Al75/SiC25 (Ferrotec)
value: 2.8
unit: g/cm3
scope: material
conditions:
composition: Al 75 vol%, SiC 25 vol%
temperature: not stated on the page
printed: '2.8'
method: Value printed on a manufacturer product web page
status: ground
source: ferrotec-alsic
where: Al / SiC Material Properties table, Density (g/cm3) row, Al75 / SiC25 column
- benchmark: density
label: Density, Al70/SiC30 (Ferrotec)
value: 2.8
unit: g/cm3
scope: material
conditions:
composition: Al 70 vol%, SiC 30 vol%
temperature: not stated on the page
printed: '2.8'
method: Value printed on a manufacturer product web page
status: ground
source: ferrotec-alsic
where: Al / SiC Material Properties table, Density (g/cm3) row, Al70 / SiC30 column
- benchmark: density
label: Density, Al60/SiC40 (Ferrotec)
value: 2.9
unit: g/cm3
scope: material
conditions:
composition: Al 60 vol%, SiC 40 vol%
temperature: not stated on the page
printed: '2.9'
method: Value printed on a manufacturer product web page
status: ground
source: ferrotec-alsic
where: Al / SiC Material Properties table, Density (g/cm3) row, Al60 / SiC40 column
- benchmark: cte
label: Coefficient of thermal expansion, Al75/SiC25 (Ferrotec)
value: 15
unit: ppm/°C
scope: material
conditions:
composition: Al 75 vol%, SiC 25 vol%
temperature: not stated on the page
printed: '15'
unit_in_source: 1/°C×10-6
method: Value printed on a manufacturer product web page
status: ground
source: ferrotec-alsic
where: Al / SiC Material Properties table, Coefficient of thermal expansion row, Al75 / SiC25 column
- benchmark: cte
label: Coefficient of thermal expansion, Al60/SiC40 (Ferrotec)
value: 13
unit: ppm/°C
scope: material
conditions:
composition: Al 60 vol%, SiC 40 vol%
temperature: not stated on the page
printed: '13'
unit_in_source: 1/°C×10-6
method: Value printed on a manufacturer product web page
status: ground
source: ferrotec-alsic
where: Al / SiC Material Properties table, Coefficient of thermal expansion row, Al60 / SiC40 column
- benchmark: density
label: Density, AlSiC-10 at 25 °C (Wikipedia)
value: 2.96
unit: g/cm3
scope: material
conditions:
grade: AlSiC-10
composition: 45 vol% A 356.2 aluminium alloy, 55 vol% SiC
temperature: 25 °C
printed: '2.96'
method: Value printed in a Wikipedia article that cites manufacturer data
status: ground
source: wikipedia-alsic
where: Grades list, AlSiC-10 entry
- benchmark: thermal_conductivity
label: Thermal conductivity, AlSiC-10 (Wikipedia)
value: 190
value_high: 200
unit: W/m K
scope: material
conditions:
grade: AlSiC-10
temperature: not stated on the page
printed: 190-200
method: Range printed in a Wikipedia article that cites manufacturer data
status: ground
source: wikipedia-alsic
where: Grades list, AlSiC-10 entry
- benchmark: thermal_conductivity
label: Thermal conductivity, AlSiC-9 (Wikipedia)
value: 190
value_high: 200
unit: W/m K
scope: material
conditions:
grade: AlSiC-9
temperature: not stated on the page
printed: 190-200
method: Range printed in a Wikipedia article that cites manufacturer data
status: ground
source: wikipedia-alsic
where: Grades list, AlSiC-9 entry
- benchmark: thermal_conductivity
label: Thermal conductivity, AlSiC-12 (Wikipedia)
value: 170
value_high: 180
unit: W/m K
scope: material
conditions:
grade: AlSiC-12
temperature: not stated on the page
printed: 170-180
method: Range printed in a Wikipedia article that cites manufacturer data
status: ground
source: wikipedia-alsic
where: Grades list, AlSiC-12 entry
corrosion: []
risks:
hazards:
- text: PubChem reports for silicon carbide (CID 9863) list H350i, May cause cancer by inhalation, with signal word Danger. The ECHA C&L aggregation says 740 of 1053 company reports did not meet GHS hazard criteria, and the record notes that classification varies with impurities, additives and form.
ghs:
- H350i
source: pubchem-sic
where: GHS Classification section, aggregated ECHA C&L notifications
- text: 'PubChem quotes IARC Vol. 111: occupational exposures in the Acheson process are Group 1, fibrous silicon carbide is Group 2B, and silicon carbide whiskers are Group 2A. PubChem also quotes ACGIH: silicon carbide fibres should be controlled like asbestos fibres, while nonfibrous particles have low to very low toxic effects on lung tissue.'
ghs: []
source: pubchem-sic
where: Hazards Summary section, quoting IARC Vol. 111 and ACGIH
- text: 'PubChem quotes the NIOSH Pocket Guide for silicon carbide: exposure by inhalation, ingestion, skin or eye contact, with symptoms of irritation of the eyes, skin and upper respiratory system, and cough.'
ghs: []
source: pubchem-sic
where: Health Hazards section, NIOSH Pocket Guide excerpt
failure_risks:
- mode: Brittle fracture under high load
trigger: Stress approaching the four-point bend strength of 488 MPa for AlSiC-9
consequence: The 2025 CPS slide prints a fracture toughness of 11.3 MPa/m2 and a percent elongation at rupture of 0.295 for AlSiC-9. The slide gives no further failure data.
severity: moderate
source: cps-alsic-2025
where: Select Material Properties table, Fracture Toughness and Percent Elongation at Rupture rows
- mode: Thermal expansion mismatch from the wrong grade
trigger: Attaching AlSiC to a chip or substrate whose expansion differs from the grade chosen
consequence: CPS prints 8.00 ppm/°C for AlSiC-9 and 10.90 ppm/°C for AlSiC-12 at 30-100 °C, so the grade sets the match. The sources read give no stress or fatigue data for a mismatched joint.
severity: moderate
source: cps-alsic-2025
where: Select Material Properties table, Thermal Expansion (CTE) row, 30-100°C line
side_effects:
- text: Silicon carbide dust from machining is the handling concern named in the sources; the CPS sheet itself names no side effect of the composite.
affects: Workers who cut, grind or drill AlSiC parts
source: pubchem-sic
where: Hazards Summary section, IARC Vol. 111 and ACGIH entries
handling:
- text: 'Name the grade on every drawing: AlSiC-9, AlSiC-10 and AlSiC-12 differ in thermal expansion, conductivity and density, per the CPS 2025 slide and Wikipedia.'
source: cps-alsic-2025
where: Select Material Properties table
- text: Control dust when cutting, grinding or drilling AlSiC. The IARC concern is fibrous silicon carbide, and PubChem quotes NIOSH for eye, skin and airway irritation from the silicon carbide dust.
source: pubchem-sic
where: Hazards Summary and Health Hazards sections
- text: 'Surface finish: Wikipedia says AlSiC can be plated with nickel or nickel-gold, or coated with other metals by thermal spraying. The sources read give no plating or corrosion test data.'
source: wikipedia-alsic
where: Manufacturing paragraph
- text: 'Plating compatibility: CPS says its AlSiC pin fin coolers support standard solderable plating schemes and Copper Cold Gas Spray. That sheet gives no corrosion result for any plated finish.'
source: cps-pinfin
where: Feature list, bullet on plating schemes
mitigations: []
uses:
- application: electronics-and-chips
device: Power semiconductor base plates and flip-chip lids
example: The CPS 2025 slide lists IGBTs for Traction, HVDC Transmission, Flip Chip Lids, Microprocessors, Traction Invertors and Optical Benches as applications. Wikipedia says AlSiC is mainly used in microelectronics as a substrate for power semiconductor devices.
source: cps-alsic-2025
where: Applications box
- application: thermal-control
device: Pin-fin and single-piece coolers for power electronics
example: The CPS 2025 slide shows a pin-fin cooler for power electronics and describes a single-piece AlSiC cooler with integrated channels, with no welding, brazing or gaskets.
source: cps-alsic-2025
where: Applications box and Single Piece Cooler section
- application: electronics-and-chips
device: Hermetic packages for military, aerospace and communications systems
example: The CPS hermetic packaging datasheet lists military, aerospace and communications systems subject to shock and vibration, and says AlSiC is 40-60% lighter than CuMo and CuW.
source: cps-hp-datasheet
where: Advantages and Applications lists
- application: rovers-and-surface-systems
device: Hermetic housing for an instrument power supply on the Perseverance rover
example: CPS states, in its company history (2020 entry), that it produced the AlSiC hermetic housing for the turret power supply of the SHERLOC instrument. This is a vendor statement.
source: cps-history
where: Our History page, 2020 entry
- application: electronics-and-chips
device: Hermetic package for GPS satellite electronics
example: CPS's company history lists a 2009 entry, CPS introduces a new AlSiC Hermetic Package GPS Satellite, and says AlSiC is also in the International Space Station and in the most recent generation of GPS satellites. These are vendor statements.
source: cps-history
where: Our History page, 2009 entry and the sentence on the International Space Station
supply:
- subject: Primary aluminium, the matrix metal
note: 'USGS 2026: world smelter production was 74,000 thousand metric tons in 2025e, of which China 45,000 and the United States 660. United States net import reliance was 60 percent of apparent consumption in 2025e. Canada supplied 56 percent of U.S. aluminium imports in 2021-24.'
producers: []
critical_lists: []
recycling: 'USGS 2026: aluminum recovered from purchased scrap in the United States was about 3.6 million tons in 2025, of which about 56% came from new scrap and 44% from old scrap.'
substitutes: []
source: usgs-mcs2026-aluminum
where: Salient Statistics table, World Smelter Production table, Import Sources and Recycling paragraphs
- subject: AlSiC composites (manufacturers named in the sources)
note: CPS Technologies, 111 S. Worcester Street, Norton, MA 02766, prints this address on its 2025 AlSiC slide. Ferrotec Advanced Ceramics publishes an Al-SiC product page; its location is not stated on the page.
producers: []
critical_lists: []
recycling: ''
substitutes: []
source: cps-alsic-2025
where: Closing contact block of the 2025 slide
story:
recipe:
line: 'AlSiC is a metal-matrix composite, not a single alloy. CPS Technologies describes a two-step process: quickset injection moulding makes a porous ceramic preform that matches the final part geometry, then pressurised melt infiltration fills the preform porosity with aluminium, giving a fully dense part with the same shape (CPS 2025 slide). Wikipedia describes the same route as injection moulding of a silicon carbide binder slurry, firing to remove the binder, then infiltration under pressure with molten aluminium.'
parts:
- name: Aluminium alloy 356 (matrix)
symbol: Al
share: 37% vol (AlSiC-9) to 63% vol (AlSiC-12)
role: Metal matrix that is infiltrated into the SiC preform. Wikipedia says the aluminium matrix has many dislocations, which give the material its strength.
- name: Silicon carbide (reinforcement)
symbol: SiC
share: 63% vol (AlSiC-9) to 37% vol (AlSiC-12)
role: Particle reinforcement that sets the thermal expansion.
why: AlSiC is used where a part must match the thermal expansion of a chip and still carry heat away while staying light. CPS Technologies prints a thermal conductivity of 190 W/mK typical at 25 °C for AlSiC-9, with a minimum of 180 W/mK, and a coefficient of thermal expansion of 8.00 ppm/°C from 30 to 100 °C. Wikipedia says the thermal expansion can be tuned to match silicon, gallium arsenide and several ceramics, and that AlSiC is mainly used in microelectronics as a substrate for power semiconductors.
can_do:
- label: Carry heat
value: 190 W/mK typical, AlSiC-9, 25 °C
benchmark: thermal_conductivity
line: CPS Technologies prints 190 W/mK typical and 180 W/mK minimum at 25 °C for AlSiC-9, and 180 W/mK typical and 170 W/mK minimum for AlSiC-12. Wikipedia gives 190-200 W/m K for AlSiC-9 and AlSiC-10, and 170-180 W/m K for AlSiC-12, without a temperature.
- label: Match a chip's expansion
value: 8.00 ppm/°C, AlSiC-9, 30-100 °C
benchmark: cte
line: CPS prints 8.00 ppm/°C from 30 to 100 °C and 8.75 ppm/°C from 30 to 200 °C for AlSiC-9. The same slide prints 10.90 ppm/°C and 11.70 ppm/°C for AlSiC-12 over the same ranges.
- label: Stay light
value: 2.89 to 3.01 g/cm3
benchmark: density
line: CPS prints 3.01 g/cm3 for AlSiC-9 and 2.89 g/cm3 for AlSiC-12. CPS's hermetic packaging datasheet says AlSiC is 40-60% lighter than CuMo and CuW.
- label: Form complex parts
value: Near net shape
line: Ferrotec lists near net shape processing as a benefit, and CPS says net-shape manufacturing removes costly machining. The sources do not give a tolerance.
compare: 'CuMo and CuW are the heat-spreader alternatives AlSiC replaces. CPS''s hermetic packaging datasheet says AlSiC is 40-60% lighter than CuMo and CuW and lower in cost. Wikipedia says AlSiC weighs about one-third as much as copper. Inside the family, the Ferrotec table shows the trade-off: going from Al75/SiC25 to Al60/SiC40 lowers the printed coefficient of thermal expansion from 15 to 13 (1/°C×10-6) and raises the printed density from 2.8 to 2.9 g/cm3. The sources give no like-for-like figure against a bare aluminium alloy, so none is stated here.'
compare_rows:
- label: Density
benchmark: density
- label: Thermal conductivity
benchmark: thermal_conductivity
- label: Thermal expansion
benchmark: cte
handling:
- 'Name the grade on every drawing: AlSiC-9, AlSiC-10 and AlSiC-12 differ in thermal expansion, conductivity and density.'
- Control silicon carbide dust when cutting, grinding or drilling. The IARC concern is fibrous silicon carbide, and PubChem quotes NIOSH for eye, skin and airway irritation.
- Plating is possible. Wikipedia says nickel or nickel-gold plating and thermal spray coatings are used, but the sources read give no corrosion data for those finishes.
good_for:
- 'Matching a chip''s expansion while removing heat: AlSiC-9 has 8.00 ppm/°C from 30 to 100 °C and 190 W/mK typical at 25 °C (CPS 2025).'
- 'Light heat spreaders and coolers: 3.01 g/cm3 for AlSiC-9, and a single-piece cooler with integrated channels (CPS 2025).'
- 'Hermetic housings: CPS says its hermetic packages use a two-step sealing process (CPS hermetic packaging datasheet).'
watch_out:
- 'Brittle at the limit: AlSiC-9 prints 11.3 MPa/m2 fracture toughness and 0.295 percent elongation at rupture (CPS 2025).'
- 'Grade choice changes the match: AlSiC-9 is 8.75 ppm/°C and AlSiC-12 is 11.70 ppm/°C at 30-200 °C (CPS 2025).'
- 'Silicon carbide dust: PubChem lists H350i for silicon carbide, and quotes IARC Vol. 111 for fibrous silicon carbide (Group 2B) and whiskers (Group 2A).'
- 'Coating data are thin: Wikipedia says nickel or nickel-gold plating is possible, but the sources read give no corrosion or galvanic test data.'
verdict: AlSiC is a light, low-expansion metal-matrix composite for power electronics and hermetic packages. The CPS 2025 slide gives the grade-level values, with 190 W/mK typical and 8.00 ppm/°C for AlSiC-9. The space uses are vendor statements from CPS's company history, and no NASA or ESA material-selection document was found in this run. Corrosion data, silicon carbide supply and fracture data for the other grades are gaps.
risk_groups:
- title: For people
lead: The silicon carbide hazard depends on the form of the dust, and the sources differ on how serious it is.
level: 1
verdict: Mixed notifications
points:
- label: Silicon carbide as a substance
line: PubChem reports H350i, May cause cancer by inhalation, with signal word Danger. The ECHA aggregation says 740 of 1053 company reports did not meet GHS hazard criteria.
- label: Fibre versus particle
line: IARC Vol. 111 lists fibrous silicon carbide as Group 2B and whiskers as Group 2A, while ACGIH says nonfibrous particles have low to very low toxic effects on lung tissue.
- label: Irritation
line: The NIOSH Pocket Guide excerpt in PubChem lists irritation of the eyes, skin and upper respiratory system, and cough.
gaps:
- Corrosion or ageing of AlSiC in air, humidity or salt was not found in the sources read. Wikipedia names nickel and nickel-gold plating, with no test data, and the galvanic points from search results were not opened as sources.
- Silicon carbide supply and production shares were not found. The USGS aluminium report was read, but no silicon carbide report was opened.
- The USGS 2026 aluminum text read does not show a critical-minerals listing, so critical_lists is empty for aluminium.
- Fracture toughness is not in the canonical property list, so it is stored as fracture_toughness with the unit printed by CPS (MPa/m2).
- CPS prints Electrical Resistance in µOhm-cm for AlSiC. It is stored as electrical_resistivity with that printed unit, and the quantity name may differ from the test method.
- CPS prints hermeticity as <10-9 atm-cm3/s He. It is not stored, because the canonical list has no helium leak-rate property.
- Temperatures and test conditions are not printed on the Ferrotec page for its volume-fraction table (density, CTE, thermal conductivity, Young's modulus). Wikipedia gives its thermal conductivity without a temperature.
- No orbit or radiation environment is set for AlSiC, because the sources name the International Space Station and GPS satellites without stating an orbit for the parts.
- Space flight use is a vendor statement from the CPS company history. No NASA or ESA material-selection document was found in this run.
- No peer-reviewed or open-access AlSiC property paper was opened. A squeeze-cast SiCp/Al study and a Rogers HEATWAVE AlSiC-8 datasheet were seen only in search snippets, and their values are not recorded.
- The density of silicon carbide itself is not stored, because no fetched page printed it.
- No machining or dust-control guidance from a supplier was found. The handling points come from the IARC, ACGIH and NIOSH text quoted by PubChem.
- Ferrotec prints its CTE unit as 1/°C×10-6. It is stored as ppm/°C with the printed unit kept in conditions.
documents:
- title: 'Wikipedia: AlSiC'
type: database
url: https://en.wikipedia.org/wiki/AlSiC
- title: Al-SiC Metal Matrix Composite Ceramic Material (Ferrotec Advanced Ceramics)
type: datasheet
url: https://ceramics.ferrotec.com/materials/metal-matrix/al-sic/
- title: CPS AlSiC Composites, 2025 product slide
type: datasheet
url: https://cpstechnologysolutions.com/wp-content/uploads/2025/09/CPS-Alsic-2025-Final.pdf
year: 2025
- title: CPS AlSiC Hermetic Packaging datasheet
type: datasheet
url: https://cpstechnologysolutions.com/wp-content/uploads/2025/01/AlSiC-HP-Data-Sheet.pdf
- title: 'Mineral Commodity Summaries 2026: Aluminum (U.S. Geological Survey)'
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-aluminum.pdf
year: 2026
- title: 'PubChem: Silicon carbide, CID 9863'
type: database
url: https://pubchem.ncbi.nlm.nih.gov/compound/Silicon-carbide
- title: AlSiC Pin Fin Coolers, CPS Technologies product sheet
type: datasheet
url: https://cpstechnologysolutions.com/wp-content/uploads/2022/03/CPS-Automotive_PinFins-Reformatted.pdf
sources:
wikipedia-alsic:
title: AlSiC
url: https://en.wikipedia.org/wiki/AlSiC
kind: web
license: CC BY-SA 4.0 (cited, not reproduced)
ferrotec-alsic:
title: Al-SiC Metal Matrix Composite Ceramic Material (Ferrotec Advanced Ceramics)
url: https://ceramics.ferrotec.com/materials/metal-matrix/al-sic/
kind: web
cps-alsic-2025:
title: CPS AlSiC Composites, 2025 product slide (Select Material Properties)
url: https://cpstechnologysolutions.com/wp-content/uploads/2025/09/CPS-Alsic-2025-Final.pdf
year: 2025
kind: datasheet
cps-hp-datasheet:
title: AlSiC Hermetic Packaging datasheet, CPS Technologies
url: https://cpstechnologysolutions.com/wp-content/uploads/2025/01/AlSiC-HP-Data-Sheet.pdf
kind: datasheet
cps-history:
title: Our History, CPS Technologies (company web page)
url: https://cpstechnologysolutions.com/our-history/
kind: web
cps-pinfin:
title: AlSiC Pin Fin Coolers, CPS Technologies product sheet
url: https://cpstechnologysolutions.com/wp-content/uploads/2022/03/CPS-Automotive_PinFins-Reformatted.pdf
kind: datasheet
usgs-mcs2026-aluminum:
title: 'Mineral Commodity Summaries 2026: Aluminum'
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-aluminum.pdf
year: 2026
kind: report
pubchem-sic:
title: PubChem, Silicon carbide, CID 9863
url: https://pubchem.ncbi.nlm.nih.gov/compound/Silicon-carbide
kind: database
license: CC-BY-4.0
updated: '2026-11-01'
review:
status: draft
method: assistant
checked_values: 33
caveats: 5
note: 'Draft profile written to the brief''s depth. Corrosion and silicon carbide supply are open gaps, and the CPS electrical resistance and fracture toughness names are not canonical. Caveats: Values were read by an AI assistant on 2026-11-01 from the pages and PDFs named in each entry (CPS slides and datasheet extracted from the PDF text; USGS aluminum text extracted from the PDF). Grade values from CPS and Ferrotec are manufacturer figures, and the grade-to-column mapping was read from the printed table. The Ferrotec and Wikipedia figures give no test temperature for most values, and are kept as printed. Space use is a vendor statement from CPS''s company history; no NASA or ESA document was read. No corrosion, supply of silicon carbide, or peer-reviewed property paper was recorded.'
References
Every number above carries a reference number. Click one to see the source and where in it the value comes from.
| # | Source | Type | Year | Used for |
|---|---|---|---|---|
| AlSiC | web | 5 values | ||
| Al-SiC Metal Matrix Composite Ceramic Material (Ferrotec Advanced Ceramics) | web | 5 values | ||
| CPS AlSiC Composites, 2025 product slide (Select Material Properties) | datasheet | 2025 | 31 values | |
| AlSiC Hermetic Packaging datasheet, CPS Technologies | datasheet | 1 value | ||
| Our History, CPS Technologies (company web page) | web | 2 values | ||
| AlSiC Pin Fin Coolers, CPS Technologies product sheet | datasheet | 1 value | ||
| Mineral Commodity Summaries 2026: Aluminum | report | 2026 | 1 value | |
| PubChem, Silicon carbide, CID 9863 | database | 5 values |
Updated