AZ91/SiC/15p T4
Temper
T4 = solution heat treated and naturally aged
Choose when the best available ductility and impact tolerance is needed from the composite.
Values for the T4 condition
Other AZ91/SiC/15p grades and fills
AZ91/SiC/15p is listed in 4 conditions; see the grade overview at AZ91/SiC/15p.
Compare all 4 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
T4This page Solution heat treated and naturally aged | Choose when the best available ductility and impact tolerance is needed from the composite. | 120 | 230 | 2.5 | — |
FDefault As fabricated | Baseline stir-cast condition: cheapest route, use where stiffness and wear matter more than strength. | 130 | 200 | 1.2 | — |
Squeeze cast / pressure infiltrated | Pick when porosity must be minimised and particle distribution uniform for fatigue-loaded parts. | 155 | 240 | 2 | — |
Solution heat treated and artificially aged | Highest hardness/yield and best wear performance; accept the loss of ductility. | 175 | 250 | 1 | — |
What is AZ91/SiC/15p T4?
AZ91/SiC/15p T4 is AZ91/SiC/15p in the T4 temper — choose when the best available ductility and impact tolerance is needed from the composite. AZ91/SiC/15p T4 has a yield strength of 120 MPa (17.4 ksi) and a tensile strength of 230 MPa (33.4 ksi) — weaker than 68% of composite grades. Elongation at break is 2.5% and the elastic modulus is 57 GPa (8.27 Msi). AZ91/SiC/15p T4 has a density of 2.02 g/cm³ (0.073 lb/in³), heavier than 78% of composite grades. F is the default condition FabDigit quotes; T4 is available on request or by drawing note.
Advantages
- Conducts heat well — 66 W/m·K (38.1 BTU/hr·ft·°F), better than 87% of composite grades
Limitations
- Needs corrosion protection — 18/100, worse than 99% of composite grades
- High embodied carbon — 30 kg CO₂/kg, worse than 80% of composite grades
- Heavy — 2.02 g/cm³ (0.073 lb/in³), worse than 78% of composite grades
- Limited service temperature — 120°C (248 °F), worse than 78% of composite grades
AZ91/SiC/15p T4 properties
Typical room-temperature values for AZ91/SiC/15p T4; 14 are specific to this condition. Other listed values are AZ91/SiC/15p reference data and may not represent this condition. Bars are the position among composite grades.
Physical1
AZ91/SiC/15p T4 has a density of 2.02 g/cm³ (0.073 lb/in³), heavier than 78% of composite grades.
Mechanical13
AZ91/SiC/15p T4 has a yield strength of 120 MPa (17.4 ksi) and a tensile strength of 230 MPa (33.4 ksi) — weaker than 68% of composite grades. Elongation at break is 2.5% and the elastic modulus is 57 GPa (8.27 Msi).
Thermal6
AZ91/SiC/15p T4 is rated for continuous service to 120°C (248 °F). It conducts heat at 66 W/m·K (38.1 BTU/hr·ft·°F), better than 87% of composite grades. Thermal expansion is 21.5 µm/m·K (11.9 µin/in·°F).
Electrical1
AZ91/SiC/15p T4 has an electrical resistivity of 2.1×10⁻⁷ Ω·m.
Chemical & Environmental3
Corrosion resistance is poor (18/100), worse than 99% of composite grades. UV resistance is fair.
Sustainability4
Producing a kilogram of AZ91/SiC/15p T4 takes about 300 MJ of energy and emits 30 kg of CO₂ — more than 68% of composite grades. Typical recycled content is 5%.
Manufacturability2
AZ91/SiC/15p T4's machinability is fair (45/100, better than 63% of composite grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with AZ91/SiC/15p T4
Is AZ91/SiC/15p easy to machine?
Highly abrasive: use PCD or diamond-coated tooling, high speed / light feed, flood or MQL coolant, and treat all Mg chips and fines as a fire hazard (never water-quench).
Can AZ91/SiC/15p be welded?
Fusion welding is generally not recommended — SiC reacts with molten Mg and porosity is severe; join by mechanical fastening, adhesive bonding or friction-stir welding with careful parameter control.
Can AZ91/SiC/15p be formed, bent or molded?
Produced by stir/compo casting or squeeze casting with degassed melt and SF6-free cover gas; cold forming is impractical, hot extrusion at 300-400 °C is possible for billet-to-bar conversion.
What surface finishes work on AZ91/SiC/15p?
Requires conversion coating or plasma-electrolytic (MAO) anodizing plus a sealer or paint; SiC particles resist the anodic film locally, so coating continuity must be inspected, and direct contact with steel or CFRP must be electrically isolated.
AZ91/SiC/15p 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 |
|---|---|---|
| SiCreinforcement: 15 vol% particulate (typ. 10-20 µm) = ~24 wt%; balance below refers to the AZ91 matrix | 20 – 27 | 23.8 |
| Almatrix basis, ASTM B93 AZ91 | 8.3 – 9.7 | 9 |
| Znmatrix basis | 0.35 – 1 | 0.7 |
| Mnmatrix basis | 0.15 – 0.5 | 0.25 |
| Simatrix impurity limit; excludes SiC reinforcement | ≤ 0.1 | — |
| Cumatrix impurity limit | ≤ 0.03 | — |
| Nimatrix impurity limit, critical for corrosion | ≤ 0 | — |
| Fematrix impurity limit, critical for corrosion | ≤ 0.01 | — |
| Mgmatrix balance | balance | — |
AZ91/SiC/15p T4 — frequently asked
What is AZ91/SiC/15p T4 used for?
AZ91/SiC/15p T4 is typically used for automotive lightweight brackets, electronic housings and aerospace lightweight castings. In short: lightest structural MMC; stiffer than cast magnesium; very low ductility.
What is the yield strength of AZ91/SiC/15p T4?
AZ91/SiC/15p T4 has a typical yield strength of 120 MPa (17.4 ksi) and a tensile strength of 230 MPa (33.4 ksi) — weaker than 68% of composite grades. Strength varies by condition: see the 4 listed tempers.
Is AZ91/SiC/15p T4 easy to machine?
Reasonably — machinability is rated fair (45/100, better than 63% of composite grades). Highly abrasive: use PCD or diamond-coated tooling, high speed / light feed, flood or MQL coolant, and treat all Mg chips and fines as a fire hazard (never water-quench).
Can AZ91/SiC/15p T4 be welded?
Fusion welding is generally not recommended — SiC reacts with molten Mg and porosity is severe; join by mechanical fastening, adhesive bonding or friction-stir welding with careful parameter control.
What surface finishes work on AZ91/SiC/15p T4?
Requires conversion coating or plasma-electrolytic (MAO) anodizing plus a sealer or paint; SiC particles resist the anodic film locally, so coating continuity must be inspected, and direct contact with steel or CFRP must be electrically isolated.
Can AZ91/SiC/15p T4 be formed, bent or molded?
Produced by stir/compo casting or squeeze casting with degassed melt and SF6-free cover gas; cold forming is impractical, hot extrusion at 300-400 °C is possible for billet-to-bar conversion.
What is the maximum service temperature of AZ91/SiC/15p T4?
AZ91/SiC/15p T4 is rated for continuous use to about 120°C (248 °F), and briefly to 200°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between AZ91/SiC/15p F and AZ91/SiC/15p T6?
F is the default condition — baseline stir-cast condition: cheapest route, use where stiffness and wear matter more than strength. T6: highest hardness/yield and best wear performance; accept the loss of ductility. Yield strength is 130 MPa in F versus 175 MPa in T6.
Sources
- ASM Handbook Vol. 21: Composites — Discontinuously Reinforced Metal-Matrix Composites — ASM International (2001)
- ASM Handbook Vol. 2: Properties and Selection — Nonferrous Alloys (AZ91 magnesium) — ASM International (1990)
- ASTM B93/B93M — Magnesium Alloys in Ingot Form for Sand, Permanent Mold and Die Castings — ASTM International (2020)
- MMC property compilations (stir-cast AZ91/SiCp studies) — open composites literature (2020)
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.