MAX phase ceramics MAX
Ti3SiC2, a layered ternary carbide of the Mn+1AXn family (n = 2, A = Si, X = C) · hexagonal, P63/mmc
Also known as Maxthal 312
MAX phases are layered hexagonal carbides and nitrides with the general formula Mn+1AXn.
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.
Stiffness, calculated
265 GPa
Hardness
4 to 6 GPa
Upper temperature
2300 °C
Recipe, share of the weight
- Ti not statedTitanium
- Si not statedSilicon
- C not statedCarbon
Best for
Electric heating elements that run hot in vacuum or inert gas, and machinable bulk parts (patent US6903313B2; Barsoum and El-Raghy 1997)
Weakest at
Oxidation in air above about 1100 to 1200 degC (patent), and decomposition into TiC above about 1400 degC in vacuum (Pang et al. 2009)
Risk at a glance
- People None found. Only vendor hazard codes; no SDS read
- If it fails Moderate. Oxidation of the carbide in air
- Corrosion Moderate. Above 1400 degC in vacuum, Ti3SiC2 starts to decompose into TiC
Quick facts: MAX
| Property | Value | Basis |
|---|---|---|
| Density | 4.47 g/cm³ | 1 sourced value |
| Yield strength | 100 MPa | 1 sourced value |
| Young's modulus | 265 GPa | 1 sourced value |
| Thermal conductivity | 43 W/(m·K) | 1 sourced value |
| Melting point | 1,390 °C | 1 sourced value |
| Maximum service temperature | 1,100 to 1,200 °C | 1 sourced value |
What is the density of MAX phase ceramics?
MAX phase ceramics has a density of 4.47 g/cm³. The source and test conditions are listed in the properties table on this page.
What is the thermal conductivity of MAX phase ceramics?
MAX phase ceramics has a thermal conductivity of 43 W/(m·K). The source and test conditions are listed in the properties table on this page.
What is the melting point of MAX phase ceramics?
MAX phase ceramics has a melting point of 1,390 °C. The source and test conditions are listed in the properties table on this page.
What is the yield strength of MAX phase ceramics?
MAX phase ceramics has a yield strength of 100 MPa. The source and test conditions are listed in the properties table on this page.
What is the Young's modulus of MAX phase ceramics?
MAX phase ceramics has a Young's modulus of 265 GPa. The source and test conditions are listed in the properties table on this page.
What is MAX phase ceramics used for?
Uses recorded in the sources include Electrical resistance heating elements for furnaces (Ti3SiC2 wire or element); Bearings and other sliding parts (candidate use); Machinable bulk parts.
Why it exists
MAX phases combine metal-like and ceramic-like behaviour. The 2009 ANSTO paper describes Ti3SiC2 as thermally shock resistant, thermally and electrically conductive, damage tolerant, lightweight, highly oxidation resistant, elastically stiff and mechanically machinable. The 1997 review gives a thermal conductivity of 43 W/m K for Ti3SiC2 and calls the 312 family as readily machinable as graphite. Ti3SiC2 is the most stable ternary in the Ti-Si-C system, and like the other MAX phases it does not melt but decomposes into its binary phases (Magnus et al. 2020).
Where it's used
Furnace heating elements
A US patent describes a Ti3SiC2 heating element for heat treatment and sintering in inert or reducing gas, in oxidizing atmospheres such as air, or in vacuum, up to 2300 degC. The 2020 Sheffield paper lists furnace tubes, burner nozzles and electric furnace elements as current uses.
Bearings and sliding parts
The 2020 Sheffield paper says the layered structure and self-lubricating properties make MAX phases a candidate for bearings and other sliding applications. This is a candidate use with no test result given here.
Machinable bulk parts
The 1997 review says these 312 ternaries machine as readily as graphite and are not susceptible to thermal shock.
Recipe
Ti3SiC2, a layered ternary carbide of the Mn+1AXn family (n = 2, A = Si, X = C)
MAX phases have the general formula Mn+1AXn. M is an early transition metal, A is an A-group element and X is carbon or nitrogen (Wikipedia, composition only). Ti3SiC2 has titanium as M, silicon as A and carbon as X, with n = 2 (Magnus et al. 2020). Bulk Ti3SiC2 is made by hot pressing or spark-plasma sintering, from TiCx and Si powders (Hwang et al. 2005) or from the commercial Maxthal 312 powder (Magnus et al. 2020; Pang et al. 2009).
| Ingredient | Share of the weight | What it does |
|---|---|---|
| Titanium Ti | not stated | The early transition metal M of the Mn+1AXn formula. Three titanium per formula unit. |
| Silicon Si | not stated | The A-group element. It is the layer that leaves the structure when Ti3SiC2 decomposes (the patent gives TiCx and Si as the breakdown products). |
| Carbon C | not stated | The X element, two carbon per formula unit, forming the carbide layers with titanium. |
Weight shares are as printed in the sources.
What it can do
Stiffness, calculated
265 GPa
worked out from the formula
A DFT study gives a calculated Young's modulus of 265 GPa for Ti2AlC (x = 0). It is calculated, not measured, and it is the only stiffness value in this file.
Hardness
4 to 6 GPa
measured
Bulk Ti3SiC2 hot pressed from TiCx and Si measured about 6 GPa (Hwang et al. 2005). A Maxthal-based composite measured 5.8 GPa (Magnus et al. 2020). The 1997 review gives a class range of 4 to 6 GPa.
Upper temperature
2300 °C
measured
The patent gives 1100 to 1200 degC in air and 2300 degC in vacuum or inert gas. These are design statements, not service tests.
How it compares
Ti3SiC2 measured in this file is denser than the calculated Ti2AlC: 4.47 g/cm3 for the Kanthal grade against 3.997 g/cm3 calculated for Ti2AlC. Thermal conductivity of 43 W/m K is measured for Ti3SiC2 in the review; no Ti2AlC conductivity is read. The Ti2AlC values are DFT results and should not be compared directly with the measured Ti3SiC2 values.
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. Other materials are shown beside it; each was measured under its own conditions, so open its page before comparing closely. Compare every grade in the family.
| Measurement | MAX | Al4C3 | B4C | HfC | Mo2C | NbC | SiC | TaC | TiC | ZrC |
|---|---|---|---|---|---|---|---|---|---|---|
| Thermal behavior and safety | ||||||||||
| Thermal conductivityValue stated in the review abstract | 43 W/m K | no data | 90 W/mK | no data | no data | no data | 4.9 W/cmK | 22 W/mK | no data | 17.5 to 31.5 W/m·K |
| Calculated melting temperature, Ti2AlC (x = 0) | 1663 K13 | 2100 °C | no data | 3890 °C | 2687 °C | 3608 °C | no data | 3880 °C | 3290 K | 3532 °C |
| Physical and electrical | ||||||||||
| Density, Maxthal 312 Ti3SiC2 bar (Kanthal grade) | 4.47 g/cm³1 | 2.36 g/cm³ | 2.5 gm/cm³ | 12.2 g/cm³ | 9.18 g/cm³ | 7.82 g/cm³ | 3.08 g/cm³ | 14.5 g/cm³ | 4.93 g/cm³ | 6.73 g/cm³ |
| Vickers hardness, Ti3SiC2 family (class range) | 4 to 6 GPa2 | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Vickers hardness, bulk Ti3SiC2 hot pressed from TiCx and Si | 6 GPa3 | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Vickers hardness, spark-plasma-sintered Maxthal 312 disc (composite) | 5.8 GPa4 | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Calculated crystal density, Ti2AlC (x = 0) | 3.997 g/cm³8 | 2.36 g/cm³ | 2.5 gm/cm³ | 12.2 g/cm³ | 9.18 g/cm³ | 7.82 g/cm³ | 3.08 g/cm³ | 14.5 g/cm³ | 4.93 g/cm³ | 6.73 g/cm³ |
| Temperature behavior | ||||||||||
| Calculated Debye temperature, Ti2AlC (x = 0) | 723 K12 | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Debye temperature from low-temperature heat capacity, Ti3AlC2 | 484.2 K14 | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Other measurements | ||||||||||
| Yield point, polycrystalline 312 ternaries at 1300 degC | 100 MPa5 | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Upper temperature limit in vacuum or inert gas | 2300 °C6 | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Upper temperature limit in air (oxidizing atmosphere) | 1100 to 1200 °C7 | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Calculated bulk modulus, Ti2AlC (x = 0) | 135 GPa9 | no data | no data | no data | no data | no data | no data | no data | 268 GPa | no data |
| Calculated shear modulus, Ti2AlC (x = 0) | 113 GPa10 | no data | no data | no data | no data | no data | no data | no data | 181 GPa | no data |
| Calculated Young's modulus, Ti2AlC (x = 0) | 265 GPa11 | no data | 440 GPa | no data | no data | no data | 395 GPa | no data | 444 GPa | 435 GPa |
| Sommerfeld coefficient, Ti3AlC2 | 4.848 mJ mol-1 K-215 | no data | no data | no data | no data | no data | no data | no data | no data | no data |
Why choose it, and why not
Good for
- Furnace heating elements in vacuum or inert gas. The patent claims use up to 2300 degC.
- Machinable, damage-tolerant bulk parts. The 1997 review calls the 312 family as machinable as graphite.
Watch out for
- Oxidation in air above about 1100 to 1200 degC, with the surface converting to TiO2 (patent).
- Commercial powder carries TiC and TiSi2 impurities at several percent, which changes its decomposition behaviour (Pang et al. 2009).
- Hazard data are thin: one vendor page, and no manufacturer safety data sheet was read.
Ti3SiC2 is a stiff, machinable carbide. Its best-sourced values are a Kanthal-grade density of 4.47 g/cm3, a thermal conductivity of 43 W/m K, and heating-element use up to 2300 degC in vacuum, with air use limited to about 1100 to 1200 degC. The Ti2AlC values are calculated, the Ti3AlC2 values are heat-capacity fits, and titanium borocarbide is not covered.
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 | Maxthal 312 |
Notes
The method, full conditions and any caveat for the numbered rows above.
| # | Measurement | Method | Conditions | Caveat |
|---|---|---|---|---|
| 1 | Density, Maxthal 312 Ti3SiC2 bar (Kanthal grade) | Density as printed by the authors with a tilde (approximately); measured on the sample | grade Maxthal Ti3SiC2 bar, 15 mm diameter, made by Kanthal's proprietary methodporosity about 1 %phases samples A and B contain TiC and TiSi2 impurities | — |
| 2 | Vickers hardness, Ti3SiC2 family (class range) | Class range stated in the review abstract; the review calls these ternaries relatively low in hardness | basis range the review gives for the 312 ternary carbides as a class (Ti3SiC2, Ti3GeC2 and Ti3AlC2), not one measured sampleload not stated | — |
| 3 | Vickers hardness, bulk Ti3SiC2 hot pressed from TiCx and Si | Vickers hardness as stated in the record abstract ('about 6 GPa') | form bulk Ti3SiC2 hot pressed from TiCx (x = 0.67) and Si at 1300 to 1500 °C in argonnote hardness falls as the indentation load rises | — |
| 4 | Vickers hardness, spark-plasma-sintered Maxthal 312 disc (composite) | Vickers microhardness measured on the polished disc; the paper gives 4 GPa for the intrinsic hardness of monolithic Ti3SiC2 for comparison | form SPS disc from Maxthal 312 powder at 99 % relative density; composite of 51.8 wt% Ti3SiC2, 36.4 wt% TiC and 11.8 wt% TiSi2load 19.6 N for 15 s | — |
| 5 | Yield point, polycrystalline 312 ternaries at 1300 degC | Yield point stated in the review abstract, described as quite high for that temperature | temperature 1300 °Cform polycrystalline 312 ternary carbide (class value) | — |
| 6 | Upper temperature limit in vacuum or inert gas | Limit stated in the patent description; a design statement, not a measured service test | atmosphere vacuum, inert or reducing atmospherebasis practical limit set in the patent because Ti3SiC2 breaks down into TiCx and Si at 2330 °C | — |
| 7 | Upper temperature limit in air (oxidizing atmosphere) | Range stated in the patent description; design statement | atmosphere oxidizing atmospheres such as air | — |
| 8 | Calculated crystal density, Ti2AlC (x = 0) | DFT calculation; density from the calculated lattice constants (Table 5). Not measured | basis calculated crystal density of the x = 0 end member, this study | — |
| 9 | Calculated bulk modulus, Ti2AlC (x = 0) | Calculated from the elastic constants in Table 2 (this study). Not measured | basis DFT elastic constants averaged to a polycrystal, this study (x = 0)pressure 0 GPa | — |
| 10 | Calculated shear modulus, Ti2AlC (x = 0) | Calculated from the elastic constants in Table 2 (this study). Not measured | basis DFT elastic constants averaged to a polycrystal, this study (x = 0) | — |
| 11 | Calculated Young's modulus, Ti2AlC (x = 0) | Calculated from the elastic constants in Table 2 (this study). Not measured | basis DFT elastic constants averaged to a polycrystal, this study (x = 0) | — |
| 12 | Calculated Debye temperature, Ti2AlC (x = 0) | Anderson method from DFT elastic constants (Table 5). Calculated, not measured | basis from the calculated average sound velocity, x = 0 | — |
| 13 | Calculated melting temperature, Ti2AlC (x = 0) | Calculated by the DFT paper (Table 5, Tm column). Not a measured melting point | basis calculated melting temperature of the x = 0 end member | — |
| 14 | Debye temperature from low-temperature heat capacity, Ti3AlC2 | Approximated Debye temperature from the authors' specific-heat fit (Table 3). The fit is representative per the paper | basis Ti3AlC2 hot-pressed bulk (x = 0 of Ti3Al1-xSixC2), linear fit of Cp/T against T squared below 7 Kmethod fit low-temperature Debye law | — |
| 15 | Sommerfeld coefficient, Ti3AlC2 | Read from the authors' specific-heat fit (Table 3) | basis electronic specific-heat coefficient from the same low-temperature fit, Ti3AlC2 bulk (x = 0) | — |
Corrosion and compatibility
What happens when it meets other materials and environments.
| Environment | Concern | What happens |
|---|---|---|
| Air at about 1000 degC, oxidation of bulk Ti3SiC2 | low | Good oxidation resistance at 1000 degC, with a parabolic rate constant that the review prints1 |
| Vacuum annealing, 1400 to 1550 degC, Maxthal Ti3SiC2 with TiC and TiSi2 | moderate | Above 1400 degC in vacuum, Ti3SiC2 starts to decompose into TiC2 |
| # | Environment | Details | Test conditions |
|---|---|---|---|
| 1 | Air at about 1000 degC, oxidation of bulk Ti3SiC2 | The 1997 review calls Ti3SiC2 highly oxidation resistant and prints a parabolic rate constant at 1000 degC in kg2 m-4 s-1 (not converted here). The patent says it resists oxidation considerably better than Ta, Mo, W and graphite, but gives no test data. It describes very good oxidation properties in air up to 1100 to 1200 degC, with a surface oxide of TiO2. The rating low is the assistant's judgement from these statements. | atmosphere airtemperature 1000 °C for the rate; up to 1100 to 1200 °C (patent) |
| 2 | Vacuum annealing, 1400 to 1550 degC, Maxthal Ti3SiC2 with TiC and TiSi2 | TiC reacts with TiSi2 between 1400 and 1450 degC to form Ti3SiC2. Above 1400 degC, Ti3SiC2 decomposes into TiC, and the rate rises with temperature and dwell time (in-situ neutron diffraction). The patent gives a decomposition temperature of 2330 degC, where Ti3SiC2 breaks down into TiCx and Si. The rating moderate is the assistant's judgement from the onset temperature. | atmosphere vacuumtemperature 1400 to 1550 °Csample Maxthal Ti3SiC2 bulk with TiC and TiSi2 impurities |
Risks and side effects
Hazards to people, what happens when a cell overheats, and how the material is handled and stored.
For people
The only hazard statements here come from one vendor product page. They include a suspected-carcinogen code (H351) and irritant codes, and the vendor says its values are theoretical. Read the manufacturer's safety data sheet before handling the powder.
- Hazard codes
- The vendor lists H315, H319, H351 and H335 with the signal word Warning. A second vendor's search result gave different codes; that listing was not read.
- Powder
- No dust, ignition or inhalation statement for Ti3SiC2 was read. Keep the powder controlled until a safety data sheet is read.
If a part overheats
These limits come from the patent and from the 2009 vacuum-annealing study.
- In air
- The patent describes use in oxidizing atmospheres up to 1100 to 1200 degC. Above this, the surface oxidizes to TiO2.
- In vacuum
- In vacuum annealing above 1400 degC, Ti3SiC2 starts to decompose into TiC, and faster at higher temperature or longer dwell.
Test details
The original wording and numbers from the sources, for readers who want them.
Failure risks
| Failure | Trigger and consequence |
|---|---|
| Oxidation of the carbide in airmoderate severity | Heating in air above about 1100 to 1200 degCThe surface oxidizes to TiO2 and the Ti3SiC2 phase is lost near the surface (patent description). |
| Decomposition into TiCmoderate severity | Vacuum annealing above about 1400 degCTi3SiC2 decomposes into TiC and silicon is lost; the rate increases with temperature and dwell time. |
| Impurity phases in commercial powderlow severity | Use of the Maxthal 312 grade with TiC and TiSi2 presentImpurity phases change the decomposition behaviour; the sample with more Ti3SiC2 decomposed less in the test. |
Mitigations
- Use the element in vacuum, inert or reducing gas above about 1100 to 1200 degC. The patent says the heating element is intended for vacuum, inert and reducing atmospheres up to 2300 degC.
Supply and geography
How common the raw materials are and where they come from.
Titanium
5,650 ppm in the Earth's crust (USGS PP 1802-A, Table A1)
- Top producers (2025)
- China 70.3%, Japan 14.3%, Russia 6.8%, Kazakhstan 4.3%, Saudi Arabia 3.2%
- Recycling
- Not stated in the USGS titanium sections read for this profile.
Aluminium (used in Ti3AlC2 and Ti2AlC)
- Top producers (2025)
- China 60.8%, India 5.7%, Russia 5.3%, Canada 4.5%
- Recycling
- USGS 2026: about 3.6 million tons of aluminum was recovered from purchased scrap in the United States in 2025.
Documents
Datasheets, safety data sheets, papers and standards you can open.
Full record
The complete spore, as stored. Free to reuse under CC-BY-4.0. Images keep the licence shown with each one.
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spore: profile
id: max-phases
spore_version: 0.2
family: carbide-nitride-boride-ceramics
name: MAX phase ceramics
abbreviation: MAX
role: layered machinable ceramic-metal hybrid for furnace heating elements, sliding parts and machinable high-temperature parts
category: ceramics
type: carbides
summary: |
MAX phases are layered hexagonal carbides and nitrides with the general formula Mn+1AXn. Titanium silicon carbide, Ti3SiC2, is the best-studied member. Bulk Ti3SiC2 is stiff and machinable, and it conducts heat and electricity like a metal. The 1997 review gives 43 W/m K for its thermal conductivity. A Kanthal grade sold as Maxthal 312 measured about 4.47 g/cm3 with about 1 % porosity. Ti2AlC values in this file are calculated (DFT) and the Ti3AlC2 values are heat-capacity fits. Oxidation data for Ti2AlC and Ti3AlC2 were not read, so they are not given.
best_for: Electric heating elements that run hot in vacuum or inert gas, and machinable bulk parts (patent US6903313B2; Barsoum and El-Raghy 1997)
weakest_at: Oxidation in air above about 1100 to 1200 degC (patent), and decomposition into TiC above about 1400 degC in vacuum (Pang et al. 2009)
identity:
formula: Ti3SiC2, a layered ternary carbide of the Mn+1AXn family (n = 2, A = Si, X = C)
crystal_system: hexagonal
space_group: P63/mmc
source: shef-magnus2020
where: 'Section 1 (Introduction): Ti3SiC2 crystallizes in the space group P63/mmc. The hexagonal structure is stated in drexel-prog312 abstract (layered structure, hexagonal)'
designations:
- system: Trade name
code: Maxthal 312
source: shef-magnus2020
where: 'Section 3.2: prealloyed Maxthal 312 powder, X-ray diffraction of the as-received powder'
tags:
environments: []
stresses:
- extreme-heat
applications:
- thermal-control
- mechanisms
- structures
properties:
- benchmark: density
label: Density, Maxthal 312 Ti3SiC2 bar (Kanthal grade)
value: 4.47
unit: g/cm3
scope: material
conditions:
grade: Maxthal Ti3SiC2 bar, 15 mm diameter, made by Kanthal's proprietary method
porosity: about 1 %
phases: samples A and B contain TiC and TiSi2 impurities
method: Density as printed by the authors with a tilde (approximately); measured on the sample
status: ground
source: ansto-pang2009
where: Experimental, Sample Preparation (first paragraph)
- benchmark: vickers_hardness
label: Vickers hardness, Ti3SiC2 family (class range)
value: 4
value_high: 6
bound: range
unit: GPa
scope: material
conditions:
basis: range the review gives for the 312 ternary carbides as a class (Ti3SiC2, Ti3GeC2 and Ti3AlC2), not one measured sample
load: not stated
method: Class range stated in the review abstract; the review calls these ternaries relatively low in hardness
status: ground
source: drexel-prog312
where: Abstract, first sentences
- benchmark: vickers_hardness
label: Vickers hardness, bulk Ti3SiC2 hot pressed from TiCx and Si
value: 6
unit: GPa
scope: material
conditions:
form: bulk Ti3SiC2 hot pressed from TiCx (x = 0.67) and Si at 1300 to 1500 degC in argon
note: hardness falls as the indentation load rises
method: Vickers hardness as stated in the record abstract ('about 6 GPa')
status: ground
source: kist-hwang2005
where: Abstract, sentence on Vickers hardness
- benchmark: vickers_hardness
label: Vickers hardness, spark-plasma-sintered Maxthal 312 disc (composite)
value: 5.8
unit: GPa
scope: material
conditions:
form: SPS disc from Maxthal 312 powder at 99 % relative density; composite of 51.8 wt% Ti3SiC2, 36.4 wt% TiC and 11.8 wt% TiSi2
load: 19.6 N for 15 s
method: Vickers microhardness measured on the polished disc; the paper gives 4 GPa for the intrinsic hardness of monolithic Ti3SiC2 for comparison
status: ground
source: shef-magnus2020
where: Section 3.2 (phase analysis, relative density) and Section 3.6 (Vickers-induced deformation)
- benchmark: thermal_conductivity
value: 43
unit: W/m K
scope: material
conditions:
basis: stated for Ti3SiC2 in the review abstract; temperature not given
method: Value stated in the review abstract
status: ground
source: drexel-prog312
where: Abstract, sentence on thermal conduction
- benchmark: yield_strength
label: Yield point, polycrystalline 312 ternaries at 1300 degC
value: 100
unit: MPa
scope: material
conditions:
temperature: 1300 degC
form: polycrystalline 312 ternary carbide (class value)
method: Yield point stated in the review abstract, described as quite high for that temperature
status: ground
source: drexel-prog312
where: Abstract, sentence on plastic deformation above 1200 degC
- benchmark: max_service_temp
label: Upper temperature limit in vacuum or inert gas
value: 2300
unit: degC
scope: material
conditions:
atmosphere: vacuum, inert or reducing atmosphere
basis: practical limit set in the patent because Ti3SiC2 breaks down into TiCx and Si at 2330 degC
method: Limit stated in the patent description; a design statement, not a measured service test
status: ground
source: us6903313
where: Description, paragraph on the decomposition temperature
- benchmark: max_service_temp
label: Upper temperature limit in air (oxidizing atmosphere)
value: 1100
value_high: 1200
bound: range
unit: degC
scope: material
conditions:
atmosphere: oxidizing atmospheres such as air
method: Range stated in the patent description; design statement
status: ground
source: us6903313
where: Description, paragraph on oxidizing atmospheres
- benchmark: density
label: Calculated crystal density, Ti2AlC (x = 0)
value: 3.997
unit: g/cm3
scope: material
conditions:
basis: calculated crystal density of the x = 0 end member, this study
method: DFT calculation; density from the calculated lattice constants (Table 5). Not measured
status: calculated
source: arxiv-2005-08604
where: Table 5, row x = 0.00, rho column
- benchmark: bulk_modulus
label: Calculated bulk modulus, Ti2AlC (x = 0)
value: 135
unit: GPa
scope: material
conditions:
basis: DFT elastic constants averaged to a polycrystal, this study (x = 0)
pressure: 0 GPa
method: Calculated from the elastic constants in Table 2 (this study). Not measured
status: calculated
source: arxiv-2005-08604
where: Table 2, row x = 0.00 (This study), B column
- benchmark: shear_modulus
label: Calculated shear modulus, Ti2AlC (x = 0)
value: 113
unit: GPa
scope: material
conditions:
basis: DFT elastic constants averaged to a polycrystal, this study (x = 0)
method: Calculated from the elastic constants in Table 2 (this study). Not measured
status: calculated
source: arxiv-2005-08604
where: Table 2, row x = 0.00 (This study), G column
- benchmark: elastic_modulus
label: Calculated Young's modulus, Ti2AlC (x = 0)
value: 265
unit: GPa
scope: material
conditions:
basis: DFT elastic constants averaged to a polycrystal, this study (x = 0)
method: Calculated from the elastic constants in Table 2 (this study). Not measured
status: calculated
source: arxiv-2005-08604
where: Table 2, row x = 0.00 (This study), Y column
- benchmark: debye_temperature
label: Calculated Debye temperature, Ti2AlC (x = 0)
value: 723
unit: K
scope: material
conditions:
basis: from the calculated average sound velocity, x = 0
method: Anderson method from DFT elastic constants (Table 5). Calculated, not measured
status: calculated
source: arxiv-2005-08604
where: Table 5, row x = 0.00, Debye temperature column
- benchmark: melting_point
label: Calculated melting temperature, Ti2AlC (x = 0)
value: 1663
unit: K
scope: material
conditions:
basis: calculated melting temperature of the x = 0 end member
method: Calculated by the DFT paper (Table 5, Tm column). Not a measured melting point
status: calculated
source: arxiv-2005-08604
where: Table 5, row x = 0.00, Tm column
- benchmark: debye_temperature
label: Debye temperature from low-temperature heat capacity, Ti3AlC2
value: 484.2
unit: K
scope: material
conditions:
basis: Ti3AlC2 hot-pressed bulk (x = 0 of Ti3Al1-xSixC2), linear fit of Cp/T against T squared below 7 K
method_fit: low-temperature Debye law
method: Approximated Debye temperature from the authors' specific-heat fit (Table 3). The fit is representative per the paper
status: ground
source: mdpi-ti3alc2-2021
where: Table 3, Ti3AlC2 row, Debye temperature column
- benchmark: sommerfeld_coefficient
label: Sommerfeld coefficient, Ti3AlC2
value: 4.848
unit: mJ mol-1 K-2
scope: material
conditions:
basis: electronic specific-heat coefficient from the same low-temperature fit, Ti3AlC2 bulk (x = 0)
method: Read from the authors' specific-heat fit (Table 3)
status: ground
source: mdpi-ti3alc2-2021
where: Table 3, Ti3AlC2 row, gamma column
corrosion:
- environment: Air at about 1000 degC, oxidation of bulk Ti3SiC2
headline: Good oxidation resistance at 1000 degC, with a parabolic rate constant that the review prints
effect: The 1997 review calls Ti3SiC2 highly oxidation resistant and prints a parabolic rate constant at 1000 degC in kg2 m-4 s-1 (not converted here). The patent says it resists oxidation considerably better than Ta, Mo, W and graphite, but gives no test data. It describes very good oxidation properties in air up to 1100 to 1200 degC, with a surface oxide of TiO2. The rating low is the assistant's judgement from these statements.
rating: low
conditions:
atmosphere: air
temperature: 1000 degC for the rate; up to 1100 to 1200 degC (patent)
source: drexel-prog312
where: Abstract (oxidation resistance); patent us6903313 description, oxidizing atmosphere paragraph
- environment: Vacuum annealing, 1400 to 1550 degC, Maxthal Ti3SiC2 with TiC and TiSi2
headline: Above 1400 degC in vacuum, Ti3SiC2 starts to decompose into TiC
effect: TiC reacts with TiSi2 between 1400 and 1450 degC to form Ti3SiC2. Above 1400 degC, Ti3SiC2 decomposes into TiC, and the rate rises with temperature and dwell time (in-situ neutron diffraction). The patent gives a decomposition temperature of 2330 degC, where Ti3SiC2 breaks down into TiCx and Si. The rating moderate is the assistant's judgement from the onset temperature.
rating: moderate
conditions:
atmosphere: vacuum
temperature: 1400 to 1550 degC
sample: Maxthal Ti3SiC2 bulk with TiC and TiSi2 impurities
source: ansto-pang2009
where: Abstract; Results, phase fraction against dwell time (Samples A and B)
risks:
hazards:
- text: 'Vendor safety statements for titanium silicon carbide (samaterials.com product page): H315, H319, H351 and H335, with the signal word Warning. The same page says its data are based on theoretical values and are for reference only. No manufacturer safety data sheet was read.'
ghs:
- H315
- H319
- H351
- H335
source: samaterials-ti3sic2
where: Product page, hazard statement line; read as a page text
failure_risks:
- mode: Oxidation of the carbide in air
trigger: Heating in air above about 1100 to 1200 degC
consequence: The surface oxidizes to TiO2 and the Ti3SiC2 phase is lost near the surface (patent description).
severity: moderate
source: us6903313
where: Description, oxidizing atmosphere paragraph
- mode: Decomposition into TiC
trigger: Vacuum annealing above about 1400 degC
consequence: Ti3SiC2 decomposes into TiC and silicon is lost; the rate increases with temperature and dwell time.
severity: moderate
source: ansto-pang2009
where: Abstract; Results, decomposition rates for Samples A and B
- mode: Impurity phases in commercial powder
trigger: Use of the Maxthal 312 grade with TiC and TiSi2 present
consequence: Impurity phases change the decomposition behaviour; the sample with more Ti3SiC2 decomposed less in the test.
severity: low
source: ansto-pang2009
where: Results, comparison of phase abundance, Samples A and B
side_effects: []
handling: []
mitigations:
- text: Use the element in vacuum, inert or reducing gas above about 1100 to 1200 degC. The patent says the heating element is intended for vacuum, inert and reducing atmospheres up to 2300 degC.
source: us6903313
where: Description, use in vacuum, inert and reducing atmospheres
uses:
- application: thermal-control
device: Electrical resistance heating elements for furnaces (Ti3SiC2 wire or element)
example: A US patent describes a heating element of Ti3SiC2 for heat treatment and sintering in inert or reducing gas, in oxidizing atmospheres or in vacuum, up to extremely high temperatures such as 2300 degC. The 2020 Sheffield paper also lists furnace tubes, high-temperature burner nozzles and electric furnace elements as current uses.
source: us6903313
where: Description, intended use paragraph; background of shef-magnus2020 (Section 1)
- application: mechanisms
device: Bearings and other sliding parts (candidate use)
example: The 2020 Sheffield paper says the layered nature and self-lubricating properties of MAX phases make them a candidate for bearings and other sliding applications. This is a candidate use, not a flight or field result.
source: shef-magnus2020
where: Section 1 (Introduction), paragraph on applications
- application: structures
device: Machinable bulk parts
example: The 1997 review says these 312 ternaries are as readily machinable as graphite and are not susceptible to thermal shock.
source: drexel-prog312
where: Abstract, sentence on machinability and thermal shock
supply:
- subject: Titanium
abundance: 5,650 ppm in the Earth's crust (USGS PP 1802-A, Table A1)
producers:
- country: China
share_percent: 70.3
year: 2025
- country: Japan
share_percent: 14.3
year: 2025
- country: Russia
share_percent: 6.8
year: 2025
- country: Kazakhstan
share_percent: 4.3
year: 2025
- country: Saudi Arabia
share_percent: 3.2
year: 2025
critical_lists: []
recycling: Not stated in the USGS titanium sections read for this profile.
substitutes: []
source: usgs-mcs2026-titanium
where: 'World Sponge Metal Production table, 2025 column (world total 370,000 t, shares calculated by Space Mushroom); Import Sources (2021-24) line. Abundance: USGS PP 1802-A, Table A1, Ti row'
- subject: Aluminium (used in Ti3AlC2 and Ti2AlC)
producers:
- country: China
share_percent: 60.8
year: 2025
- country: India
share_percent: 5.7
year: 2025
- country: Russia
share_percent: 5.3
year: 2025
- country: Canada
share_percent: 4.5
year: 2025
critical_lists: []
recycling: 'USGS 2026: about 3.6 million tons of aluminum was recovered from purchased scrap in the United States in 2025.'
substitutes: []
source: usgs-mcs2026-aluminum
where: World Smelter Production table, 2025e column (world total 74,000 as printed; shares calculated by Space Mushroom); Recycling paragraph
media: []
documents:
- title: Barsoum and El-Raghy, A Progress Report on Ti3SiC2, Ti3GeC2 and the H-phases, M2BX, J. Materials Synthesis and Processing 5, 197-216 (1997)
type: paper
url: https://research.coe.drexel.edu/mse/layeredsolids/wp-content/uploads/2011/01/Prog_rep_312.htm
year: 1997
- title: Hwang, Park and Kim, Mechanical properties of synthesized Ti3SiC2 by hot pressing from TiCx/Si powder mixture, KIST repository record (Key Engineering Materials 287, 2005)
type: paper
url: https://pubs.kist.re.kr/handle/201004/136659
year: 2005
- title: Magnus et al., Synthesis and microstructural evolution in ternary metalloceramic Ti3SiC2 consolidated via the Maxthal 312 powder route, Ceramics International 46 (2020) 15342-15356
type: paper
url: https://sheffield.ac.uk/media/29142/download
year: 2020
- title: Pang et al., Effect of Vacuum Annealing on the Thermal Stability of Ti3SiC2/TiC/TiSi2 Composites, Journal of the Australian Ceramic Society 45(1), 72-77 (2009)
type: paper
url: https://apo.ansto.gov.au/bitstreams/aeb3b687-f63e-76a5-e053-150a9d89ded9/download
year: 2009
- title: Structure, Morphology, Heat Capacity, and Electrical Transport Properties of Ti3(Al,Si)C2 Materials, Materials 14(12), 3222 (2021), open access
type: paper
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8230697/
year: 2021
- title: 'Recently synthesized (Ti1-xMox)2AlC (0 < x < 0.20) solid solutions: DFT study of structure, mechanics and thermodynamics (arXiv 2005.08604)'
type: paper
url: https://arxiv.org/pdf/2005.08604
year: 2020
- title: US patent US6903313B2, Resistance heating element for extreme temperatures
type: report
url: https://patents.google.com/patent/US6903313B2/en
- title: Wikipedia, MAX phases (composition, structure and history only)
type: database
url: https://en.wikipedia.org/wiki/MAX_phases
- title: 'Vendor product page, titanium silicon carbide Ti3SiC2 (samaterials.com): hazard statements and density'
type: datasheet
url: https://samaterials.com/cm6197-titanium-silicon-carbide-ti3sic2.html
- title: USGS Mineral Commodity Summaries 2026, Titanium and Titanium Dioxide
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-titanium.pdf
year: 2026
- title: USGS Mineral Commodity Summaries 2026, Aluminum
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-aluminum.pdf
year: 2026
- title: USGS Professional Paper 1802-A, Table A1 crustal abundances
type: report
url: https://pubs.usgs.gov/pp/1802/a/pp1802a.pdf
year: 2017
gaps:
- Titanium borocarbide, named in the brief as a MAX phase, has no source read in this run, so it is not covered here.
- 'Ti2AlC and Ti3AlC2 oxidation: the open papers were blocked or unreadable (RSC, Taylor and Francis, HAL, NSF PAR, Curtin). Only search snippets were seen, so no oxidation value is used for them.'
- Measured density, hardness and elastic moduli of Ti2AlC and Ti3AlC2 were not read from a fetched page. The Ti2AlC values in this file are DFT results only.
- Measured Young's modulus (283 GPa) and fracture toughness of Ti3SiC2 from Gao et al. 1998 (Springer) could not be opened, so they are not used.
- Electrical conductivity of Ti3SiC2 (1997 review) is printed with a garbled unit symbol, so it is not used. Thermal conductivity and thermal expansion of Ti2AlC and Ti3AlC2 were not read.
- Ti2AlC thermal expansion (8.2 x 10-6 K-1) appears in the DFT paper introduction, citing another work. It was not converted, so it is not used.
- Debye temperature, Sommerfeld coefficient and vickers_hardness are not canonical names in property-canon.yaml. They are used as snake_case names and noted here.
- 'No CAS number: the vendor page that prints it could not be opened, so cas is left out.'
- 'Designations: no fetched source printed a UNS, EN, DIN or JIS code for Ti3SiC2. Only the trade name Maxthal 312 is listed.'
- 'Hazard data: one vendor page only, which says its values are theoretical. A second vendor''s search snippet gives a different signal word and codes; it was not read. No manufacturer safety data sheet was read, so handling is empty.'
- Silicon supply (production and critical-list status) and aluminium crustal abundance were not read in this run. The titanium critical-minerals listing could not be confirmed (USGS critical-minerals page blocked), so critical_lists is empty.
- 'Environments: no source read supports a space environment tag, so tags.environments is empty. Radiation tolerance is mentioned in the Sheffield introduction with references that were not read.'
- Synthesis route of the commercial grade is proprietary (Kanthal), per the ANSTO paper. No production route for pure Ti3SiC2 was read.
sources:
drexel-prog312:
title: Barsoum and El-Raghy, A Progress Report on Ti3SiC2, Ti3GeC2 and the H-phases, M2BX, J. Materials Synthesis and Processing 5, 197-216 (1997)
url: https://research.coe.drexel.edu/mse/layeredsolids/wp-content/uploads/2011/01/Prog_rep_312.htm
kind: paper
license: Drexel University web copy, cited not reproduced
kist-hwang2005:
title: Hwang, Park and Kim, Mechanical properties of synthesized Ti3SiC2 by hot pressing from TiCx/Si powder mixture (Key Engineering Materials 287, 2005; DOI 10.4028/www.scientific.net/KEM.287.194)
url: https://pubs.kist.re.kr/handle/201004/136659
kind: paper
license: KIST repository record, cited not reproduced
shef-magnus2020:
title: Magnus et al., Synthesis and microstructural evolution in ternary metalloceramic Ti3SiC2 consolidated via the Maxthal 312 powder route, Ceramics International 46 (2020) 15342-15356
url: https://sheffield.ac.uk/media/29142/download
kind: paper
license: Accepted author copy hosted by the University of Sheffield, cited not reproduced
ansto-pang2009:
title: Pang et al., Effect of Vacuum Annealing on the Thermal Stability of Ti3SiC2/TiC/TiSi2 Composites, Journal of the Australian Ceramic Society 45(1), 72-77 (2009)
url: https://apo.ansto.gov.au/bitstreams/aeb3b687-f63e-76a5-e053-150a9d89ded9/download
kind: paper
license: ANSTO repository, cited not reproduced
mdpi-ti3alc2-2021:
title: Structure, Morphology, Heat Capacity, and Electrical Transport Properties of Ti3(Al,Si)C2 Materials, Materials 14(12), 3222 (2021)
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8230697/
kind: paper
license: CC BY 4.0 (open access)
arxiv-2005-08604:
title: 'Recently synthesized (Ti1-xMox)2AlC (0 < x < 0.20) solid solutions: deciphering the structural, electronic, mechanical and thermodynamic properties via ab initio simulations (arXiv 2005.08604)'
url: https://arxiv.org/pdf/2005.08604
kind: paper
license: arXiv preprint, cited not reproduced
us6903313:
title: US patent US6903313B2, Resistance heating element for extreme temperatures
url: https://patents.google.com/patent/US6903313B2/en
kind: web
license: patent document, cited not reproduced
wiki-max-phases:
title: Wikipedia, MAX phases (used for composition, structure and history only)
url: https://en.wikipedia.org/wiki/MAX_phases
kind: web
license: CC BY-SA 4.0
samaterials-ti3sic2:
title: Vendor product page, titanium silicon carbide (Ti3SiC2), samaterials.com (hazard statements; values marked theoretical)
url: https://samaterials.com/cm6197-titanium-silicon-carbide-ti3sic2.html
kind: datasheet
license: vendor product page, cited not reproduced
usgs-mcs2026-titanium:
title: USGS Mineral Commodity Summaries 2026, Titanium and Titanium Dioxide
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-titanium.pdf
kind: report
license: public domain (USGS)
usgs-mcs2026-aluminum:
title: USGS Mineral Commodity Summaries 2026, Aluminum
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-aluminum.pdf
kind: report
license: public domain (USGS)
usgs-pp1802a:
title: USGS Professional Paper 1802-A, Critical Mineral Resources of the United States, Table A1 (crustal abundances)
url: https://pubs.usgs.gov/pp/1802/a/pp1802a.pdf
kind: report
license: public domain (USGS)
license: CC-BY-4.0
updated: '2026-10-26'
review:
status: draft
method: assistant
checked_values: 16
unreachable: 6
caveats: 8
note: 'Written in this run from pages read in this run: the Barsoum and El-Raghy 1997 review (Drexel), the KIST 2005 record, the Magnus et al. 2020 Sheffield PDF, the Pang et al. 2009 ANSTO PDF, the Materials 2021 open-access paper (PMC8230697), the arXiv 2005.08604 DFT paper, the US6903313 patent, Wikipedia (composition and history only), the samaterials.com product page (read by WebFetch), and the USGS titanium, aluminum and PP 1802-A documents. Unreachable: Springer (Gao 1998), RSC, Taylor and Francis (Tallman 2013), MDPI landing pages, American Elements (bot check), HAL, NSF PAR, Curtin and the USGS critical-minerals page.'
story:
recipe:
line: MAX phases have the general formula Mn+1AXn. M is an early transition metal, A is an A-group element and X is carbon or nitrogen (Wikipedia, composition only). Ti3SiC2 has titanium as M, silicon as A and carbon as X, with n = 2 (Magnus et al. 2020). Bulk Ti3SiC2 is made by hot pressing or spark-plasma sintering, from TiCx and Si powders (Hwang et al. 2005) or from the commercial Maxthal 312 powder (Magnus et al. 2020; Pang et al. 2009).
parts:
- name: Titanium
symbol: Ti
role: The early transition metal M of the Mn+1AXn formula. Three titanium per formula unit.
- name: Silicon
symbol: Si
role: The A-group element. It is the layer that leaves the structure when Ti3SiC2 decomposes (the patent gives TiCx and Si as the breakdown products).
- name: Carbon
symbol: C
role: The X element, two carbon per formula unit, forming the carbide layers with titanium.
risk_groups:
- title: For people
level: 0
verdict: Only vendor hazard codes; no SDS read
lead: The only hazard statements here come from one vendor product page. They include a suspected-carcinogen code (H351) and irritant codes, and the vendor says its values are theoretical. Read the manufacturer's safety data sheet before handling the powder.
points:
- label: Hazard codes
line: The vendor lists H315, H319, H351 and H335 with the signal word Warning. A second vendor's search result gave different codes; that listing was not read.
- label: Powder
line: No dust, ignition or inhalation statement for Ti3SiC2 was read. Keep the powder controlled until a safety data sheet is read.
- title: If a part overheats
lead: These limits come from the patent and from the 2009 vacuum-annealing study.
points:
- label: In air
line: The patent describes use in oxidizing atmospheres up to 1100 to 1200 degC. Above this, the surface oxidizes to TiO2.
- label: In vacuum
line: In vacuum annealing above 1400 degC, Ti3SiC2 starts to decompose into TiC, and faster at higher temperature or longer dwell.
why: MAX phases combine metal-like and ceramic-like behaviour. The 2009 ANSTO paper describes Ti3SiC2 as thermally shock resistant, thermally and electrically conductive, damage tolerant, lightweight, highly oxidation resistant, elastically stiff and mechanically machinable. The 1997 review gives a thermal conductivity of 43 W/m K for Ti3SiC2 and calls the 312 family as readily machinable as graphite. Ti3SiC2 is the most stable ternary in the Ti-Si-C system, and like the other MAX phases it does not melt but decomposes into its binary phases (Magnus et al. 2020).
uses:
- where: Furnace heating elements
line: A US patent describes a Ti3SiC2 heating element for heat treatment and sintering in inert or reducing gas, in oxidizing atmospheres such as air, or in vacuum, up to 2300 degC. The 2020 Sheffield paper lists furnace tubes, burner nozzles and electric furnace elements as current uses.
- where: Bearings and sliding parts
line: The 2020 Sheffield paper says the layered structure and self-lubricating properties make MAX phases a candidate for bearings and other sliding applications. This is a candidate use with no test result given here.
- where: Machinable bulk parts
line: The 1997 review says these 312 ternaries machine as readily as graphite and are not susceptible to thermal shock.
can_do:
- label: Stiffness, calculated
benchmark: elastic_modulus
line: A DFT study gives a calculated Young's modulus of 265 GPa for Ti2AlC (x = 0). It is calculated, not measured, and it is the only stiffness value in this file.
- label: Hardness
benchmark: vickers_hardness
line: Bulk Ti3SiC2 hot pressed from TiCx and Si measured about 6 GPa (Hwang et al. 2005). A Maxthal-based composite measured 5.8 GPa (Magnus et al. 2020). The 1997 review gives a class range of 4 to 6 GPa.
- label: Upper temperature
benchmark: max_service_temp
line: The patent gives 1100 to 1200 degC in air and 2300 degC in vacuum or inert gas. These are design statements, not service tests.
compare: 'Ti3SiC2 measured in this file is denser than the calculated Ti2AlC: 4.47 g/cm3 for the Kanthal grade against 3.997 g/cm3 calculated for Ti2AlC. Thermal conductivity of 43 W/m K is measured for Ti3SiC2 in the review; no Ti2AlC conductivity is read. The Ti2AlC values are DFT results and should not be compared directly with the measured Ti3SiC2 values.'
compare_rows:
- label: Density
benchmark: density
- label: Thermal conductivity
benchmark: thermal_conductivity
- label: Hardness
benchmark: vickers_hardness
handling:
- Keep heating-element service in air below about 1100 to 1200 degC (patent).
- Commercial grades carry TiC and TiSi2. In vacuum above about 1400 degC they can decompose further (Pang et al. 2009).
- No safety data sheet was read, so no powder handling rule is sourced here.
good_for:
- Furnace heating elements in vacuum or inert gas. The patent claims use up to 2300 degC.
- Machinable, damage-tolerant bulk parts. The 1997 review calls the 312 family as machinable as graphite.
watch_out:
- Oxidation in air above about 1100 to 1200 degC, with the surface converting to TiO2 (patent).
- Commercial powder carries TiC and TiSi2 impurities at several percent, which changes its decomposition behaviour (Pang et al. 2009).
- 'Hazard data are thin: one vendor page, and no manufacturer safety data sheet was read.'
verdict: Ti3SiC2 is a stiff, machinable carbide. Its best-sourced values are a Kanthal-grade density of 4.47 g/cm3, a thermal conductivity of 43 W/m K, and heating-element use up to 2300 degC in vacuum, with air use limited to about 1100 to 1200 degC. The Ti2AlC values are calculated, the Ti3AlC2 values are heat-capacity fits, and titanium borocarbide is not covered.
References
Every number above carries a reference number. Click one to see the source and where in it the value comes from.