LAS/SiC
also Blackglas
LAS/SiC is a glass-ceramic matrix composite — lithium aluminosilicate, with related CAS, BMAS and borosilicate matrices — reinforced with SiC or carbon fiber or SiC whiskers; Blackglas variants use a polymer-derived matrix built up by repeated pyrolysis.
Reference datasheet — LAS/SiC is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the LAS-2D condition
LAS/SiC grades and fills
LAS/SiC is supplied in 8 conditions, soft to hard. LAS-2D is the default FabDigit quotes; the values on this page are for it.
Compare all 8 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
SiC whisker / particulate reinforced LAS glass-ceramic | Discontinuous reinforcement for near-net-shape, isotropic parts where cost matters more than toughness. | 150 | 0.15 | ||
polymer-derived SiOC (black glass) matrix with SiC or C fiber | Resin-transfer/prepreg route via siloxane precursor pyrolysis — pick it for large, complex, low-cost CMC shells rather than peak properties. | 250 | 0.5 | ||
LAS-2DDefault 2D woven SiC (Nicalon) fiber / lithium aluminosilicate matrix | General-purpose plate/panel lay-up: balanced in-plane properties for structural CMC panels and heat-shield hardware. | 260 | 0.7 | ||
calcium aluminosilicate matrix with SiC fiber | Higher-temperature, lithium-free matrix; better creep and steam resistance than LAS at 1000–1100 °C. | 300 | 0.8 | ||
barium magnesium aluminosilicate matrix with SiC fiber | Top-end glass-ceramic matrix for the hottest service (up to ~1200 °C) and best oxidation stability of this family. | 320 | 0.7 | ||
borosilicate glass matrix with SiC fiber | Lowest-cost, lowest-temperature member: easy hot-press consolidation, high room-temperature strength, but softens above ~600 °C. | 500 | 0.9 | ||
Carbon fiber reinforced glass-ceramic matrix | Highest stiffness and truly near-zero CTE for space optics/benches, but only usable in vacuum or inert atmosphere above ~450 °C. | 600 | 0.6 | ||
Unidirectional SiC fiber / LAS glass-ceramic | Choose when load path is one-dimensional (struts, booms, tensile test coupons) and maximum axial strength/toughness is needed. | 700 | 0.9 |
Supply forms, finishes and certifications
Ways LAS/SiC is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
SEALCOAT | Seal-coated | Surface finish |
What is LAS/SiC?
LAS/SiC is a glass-ceramic matrix composite — lithium aluminosilicate, with related CAS, BMAS and borosilicate matrices — reinforced with SiC or carbon fiber or SiC whiskers; Blackglas variants use a polymer-derived matrix built up by repeated pyrolysis. It is consolidated at relatively low temperature and then cerammed, giving 260 MPa tensile strength, 110 GPa modulus and 0.7% elongation with service to 900 °C, which suits radomes and moderate-temperature aerospace structures. The 900 °C ceiling is far below SiC/SiC or C/SiC, machined edges delaminate easily, and an oxidation seal coat is normally required. SiC/SiC is the step up above 900 °C. LAS/SiC has a density of 2.5 g/cm³ (0.0903 lb/in³), heavier than 81% of composite grades. LAS/SiC has a tensile strength of 260 MPa (37.7 ksi), stronger than 51% of composite grades. Elongation at break is 0.7% and the elastic modulus is 110 GPa (16 Msi).
What is LAS/SiC used for?
- radomes
- missile structural components
- heat exchanger parts
- aerospace secondary structures
Advantages
- High service temperature — 900°C (1,652 °F), better than 91% of composite grades
- Good UV / weathering resistance — 98/100, better than 85% of composite grades
Limitations
- Difficult to machine — 8/100, worse than 94% of composite grades
- Limited ductility — 0.7%, worse than 86% of composite grades
- Heavy — 2.5 g/cm³ (0.0903 lb/in³), worse than 81% of composite grades
LAS/SiC properties
Typical room-temperature values for LAS/SiC-LAS-2D; bars are the position among composite grades.
Physical2
LAS/SiC has a density of 2.5 g/cm³ (0.0903 lb/in³), heavier than 81% of composite grades.
Mechanical12
LAS/SiC has a tensile strength of 260 MPa (37.7 ksi), stronger than 51% of composite grades. Elongation at break is 0.7% and the elastic modulus is 110 GPa (16 Msi).
Thermal7
LAS/SiC is rated for continuous service to 900°C (1,652 °F). It conducts heat at 2.5 W/m·K (1.44 BTU/hr·ft·°F), better than 61% of composite grades. Thermal expansion is 3 µm/m·K (1.67 µin/in·°F).
Electrical1
LAS/SiC has an electrical resistivity of 1 Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (78/100), worse than 52% of composite grades. UV resistance is excellent.
Sustainability3
Producing a kilogram of LAS/SiC takes about 320 MJ of energy and emits 26 kg of CO₂ — more than 72% of composite grades. Typical recycled content is 0%.
Manufacturability2
LAS/SiC's machinability is not recommended (8/100, worse than 94% of composite grades).
Common Calculations4
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the composite family
Yield strength against density for every composite grade FabDigit runs. LAS/SiC is highlighted; hover a dot for its name, or open the interactive family chart.
Working with LAS/SiC
Is LAS/SiC easy to machine?
Diamond grinding, ultrasonic or waterjet/laser cutting only; avoid drilling near edges to prevent delamination and fiber pull-out.
Can LAS/SiC be welded?
Not weldable — join by brazing with active (Ti-containing) filler, glass sealing or mechanical/pinned attachments.
Can LAS/SiC be formed, bent or molded?
Fiber tow slurry impregnation into prepreg, lay-up, then hot pressing in the glassy state (~1200–1400 °C) followed by a ceramming/crystallisation hold; Blackglas variants use RTM/prepreg plus repeated polymer pyrolysis cycles.
LAS/SiC 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 |
|---|---|---|
| SiC fiber (Nicalon / Hi-Nicalon)vol % continuous fiber, with C or BN interphase ~0.1–1 µm | 30 – 50 | 40 |
| SiO2matrix oxide basis | 55 – 72 | 65 |
| Al2O3matrix oxide basis | 15 – 27 | 21 |
| Li2Oβ-spodumene/β-quartz former, gives near-zero CTE | 3 – 6 | 4.5 |
| MgO | 0 – 2 | 1 |
| ZnO | 0 – 2 | 1 |
| TiO2 + ZrO2nucleating agents for crystallisation | 2 – 6 | 4 |
| Nb2O5 / Ta2O5added in Corning-type LAS-III to improve fiber/matrix stability | 0 – 4 | 2 |
What surface finishes work on LAS/SiC?
Seal coat with CVD SiC or a glass overlay for oxidation protection; surfaces can be lapped but fiber texture limits optical polish.
Equivalent designations
Standards and trade names that resolve to LAS/SiC in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- Blackglas
How much does LAS/SiC cost?
LAS/SiC is a high-cost composite ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
LAS/SiC — frequently asked
What is LAS/SiC used for?
LAS/SiC is typically used for radomes, missile structural components, heat exchanger parts and aerospace secondary structures. In short: low-temperature-processed CMC; radome-grade glass ceramic; 900 °C service ceiling.
What is the tensile strength of LAS/SiC?
LAS/SiC has a typical tensile strength of 260 MPa (37.7 ksi) — stronger than 51% of composite grades. Strength varies by condition: see the 8 listed tempers.
Is LAS/SiC easy to machine?
Not especially — machinability is rated not recommended (8/100, worse than 94% of composite grades). Diamond grinding, ultrasonic or waterjet/laser cutting only; avoid drilling near edges to prevent delamination and fiber pull-out.
Can LAS/SiC be welded?
Not weldable — join by brazing with active (Ti-containing) filler, glass sealing or mechanical/pinned attachments.
What surface finishes work on LAS/SiC?
Seal coat with CVD SiC or a glass overlay for oxidation protection; surfaces can be lapped but fiber texture limits optical polish.
Can LAS/SiC be formed, bent or molded?
Fiber tow slurry impregnation into prepreg, lay-up, then hot pressing in the glassy state (~1200–1400 °C) followed by a ceramming/crystallisation hold; Blackglas variants use RTM/prepreg plus repeated polymer pyrolysis cycles.
What is the maximum service temperature of LAS/SiC?
LAS/SiC is rated for continuous use to about 900°C (1,652 °F), and briefly to 1,200°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does LAS/SiC cost?
LAS/SiC is a high-cost composite ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- Engineered Materials Handbook Vol. 4: Ceramics and Glasses (CMC section) — ASM International (1991)
- Ceramic Matrix Composites: Fiber Reinforced Ceramics and their Applications — Wiley-VCH (2008)
- Compglas SiC fiber reinforced glass-ceramic composite data — Corning Incorporated (1990)
- Blackglas ceramic composite (SiOC matrix) technical bulletin — AlliedSignal / Northrop Grumman (1998)
- NIST/NASA structural ceramics and CMC property compilations — NASA Glenn Research Center (2005)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.