HPSiC HP-AL
Grade
HP-AL = hot pressed with Al₂O₃/Y₂O₃ (liquid-phase) aids
Pick the liquid-phase Al₂O₃/Y₂O₃-aided hot pressed (LPS) grade for higher strength and toughness in wear-resistant structural parts, accepting 70 W/m·K and a 1400 °C limit.
Values for the HP-AL condition
Other HPSiC tempers and conditions
HPSiC is listed in 3 conditions; see the grade overview at HPSiC.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
HP-ALThis page Hot pressed with Al₂O₃/Y₂O₃ (liquid-phase) aids | Pick the liquid-phase Al₂O₃/Y₂O₃-aided hot pressed (LPS) grade for higher strength and toughness in wear-resistant structural parts, accepting 70 W/m·K and a 1400 °C limit. | — | — | — | 2,300 HV | 70 W/m·K |
HP-BCDefault Hot pressed with boron + carbon sintering aids | Choose this general-purpose hot pressed grade with boron and carbon aids for armor plate, seal rings and nozzles needing peak hardness, 125 W/m·K and 1600 °C service; machinability is only 3. | — | — | — | 2,600 HV | 125 W/m·K |
Hot isostatic pressed | Specify hot isostatic pressing for zero porosity and ultrafine grain — highest-strength armor, precision optical mirror blanks and post-densification of complex hot pressed shapes — at machinability 2. | — | — | — | 2,700 HV | 130 W/m·K |
What is HPSiC HP-AL?
HPSiC HP-AL is HPSiC in the HP-AL grade — pick the liquid-phase Al₂O₃/Y₂O₃-aided hot pressed (LPS) grade for higher strength and toughness in wear-resistant structural parts, accepting 70 W/m·K and a 1400 °C limit. HPSiC HP-AL has a tensile strength of 350 MPa (50.8 ksi), stronger than 71% of ceramic grades. The elastic modulus is 420 GPa (60.9 Msi). HPSiC HP-AL has a density of 3.24 g/cm³ (0.117 lb/in³), lighter than 70% of ceramic grades. It melts at 2,730°C (4,946 °F). HP-BC is the default condition FabDigit quotes; HP-AL is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 92/100, better than 89% of ceramic grades
- High service temperature — 1,400°C (2,552 °F), better than 77% of ceramic grades
HPSiC HP-AL properties
Typical room-temperature values for HPSiC HP-AL; 10 are specific to this condition. Other listed values are HPSiC reference data and may not represent this condition. Bars are the position among ceramic grades.
Physical3
HPSiC HP-AL has a density of 3.24 g/cm³ (0.117 lb/in³), lighter than 70% of ceramic grades. It melts at 2,730°C (4,946 °F).
Mechanical12
HPSiC HP-AL has a tensile strength of 350 MPa (50.8 ksi), stronger than 71% of ceramic grades. The elastic modulus is 420 GPa (60.9 Msi).
Thermal5
HPSiC HP-AL is rated for continuous service to 1,400°C (2,552 °F). It conducts heat at 70 W/m·K (40.4 BTU/hr·ft·°F), better than 70% of ceramic grades. Thermal expansion is 4 µm/m·K (2.22 µin/in·°F).
Electrical2
HPSiC HP-AL has an electrical resistivity of 10 Ω·m.
Chemical & Environmental2
Corrosion resistance is excellent (85/100), better than 69% of ceramic grades.
Sustainability4
Producing a kilogram of HPSiC HP-AL takes about 130 MJ of energy and emits 11 kg of CO₂ — more than 55% of ceramic grades. Typical recycled content is 0%.
Manufacturability3
HPSiC HP-AL's machinability is not recommended (4/100, worse than 85% of ceramic grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with HPSiC HP-AL
Is HPSiC easy to machine?
After sintering only diamond wheel grinding, ultrasonic or laser machining is possible; rough the green (pre-pressed) body with carbide tooling to reduce cost.
Can HPSiC be welded?
Not weldable; join by active-metal brazing (Ti/Ag-Cu), diffusion bonding or reaction bonding with a Si/C interlayer.
Can HPSiC be formed, bent or molded?
Uniaxial hot pressing in graphite dies yields only simple shapes such as plates, blocks and discs; complex geometry must be pressed or isostatically formed first and then densified by HIP.
What surface finishes work on HPSiC?
Can be precision lapped and polished to Ra <0.02 µm (optical parts are polished after a Si cladding layer is applied); a CVD-SiC coating can be used to seal the surface and improve surface integrity.
HPSiC chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Bboron sintering aid (HP-BC type), usually added as B₄C | 0.2 – 1 | 0.5 |
| C (free)free carbon, removes surface SiO₂ | 0.3 – 2 | 1 |
| Al2O3only in liquid-phase HP-AL type, usually with Y₂O₃ | 0 – 3 | 0 |
| Y2O3only in liquid-phase HP-AL type | 0 – 2 | 0 |
| Feimpurity introduced by ball milling | 0 – 0.1 | 0.03 |
| SiCα-SiC (6H) main phase, fine grain 1–5 µm | ≥ 97 (balance) | — |
HPSiC HP-AL — frequently asked
What is HPSiC HP-AL used for?
HPSiC HP-AL is typically used for ceramic armor, ballistic tiles, high-precision wear components and optical mirror substrates. In short: highest-density SiC route; simple shapes only; armor-grade fine grain.
What is the tensile strength of HPSiC HP-AL?
HPSiC HP-AL has a typical tensile strength of 350 MPa (50.8 ksi) — stronger than 71% of ceramic grades. Strength varies by condition: see the 3 listed tempers.
Is HPSiC HP-AL easy to machine?
Not especially — machinability is rated not recommended (4/100, worse than 85% of ceramic grades). After sintering only diamond wheel grinding, ultrasonic or laser machining is possible; rough the green (pre-pressed) body with carbide tooling to reduce cost.
Can HPSiC HP-AL be welded?
Not weldable; join by active-metal brazing (Ti/Ag-Cu), diffusion bonding or reaction bonding with a Si/C interlayer.
What surface finishes work on HPSiC HP-AL?
Can be precision lapped and polished to Ra <0.02 µm (optical parts are polished after a Si cladding layer is applied); a CVD-SiC coating can be used to seal the surface and improve surface integrity.
Can HPSiC HP-AL be formed, bent or molded?
Uniaxial hot pressing in graphite dies yields only simple shapes such as plates, blocks and discs; complex geometry must be pressed or isostatically formed first and then densified by HIP.
What is the maximum service temperature of HPSiC HP-AL?
HPSiC HP-AL is rated for continuous use to about 1,400°C (2,552 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASM Engineered Materials Handbook Vol. 4: Ceramics and Glasses — ASM International (1991)
- Silicon Carbide Material Properties (hot-pressed / sintered grades) — CoorsTek (2023)
- Fine Ceramics Technical Data — SiC — Kyocera (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.