AlSi11Cu2 (A383)

AlSi11Cu2, known as A383 in the USA or ADC12 in Japan, is an Al-Si-Cu casting alloy of the 3xx.x series and the most widely used aluminum die casting alloy in the world. Its high silicon content (~11%) combined with copper gives it exceptional fluidity, good mechanical strength, and excellent machinability. It is used mainly in die cast automotive parts such as transmission cases, engine covers, and brackets, as well as in electronics, appliances, and telecom.

Its composition is aluminum (balance) with silicon between 9.5–11.5% and copper between 1.5–3.5%, plus limits for iron (≤1.00%), magnesium (≤0.30%), manganese (≤0.50%), zinc (≤1.00%), and nickel (≤0.30%). The high silicon provides the exceptional fluidity needed for thin-wall parts, while copper improves mechanical strength and machinability. Its tolerance for iron levels up to ≤1.00% makes it compatible with secondary aluminum.

AlSi11Cu2 is optimized for high-pressure die casting, which is its dominant application worldwide. Its exceptional fluidity allows it to fill thin-wall die cast parts and delivers excellent dimensional reproducibility. Its melting range is 516–582 °C and its density is 2.74 g/cm³.

In its typical as-cast die casting condition it offers a tensile strength (UTS) of 310–330 MPa, a yield strength of 150–170 MPa, elongation of 2–4%, and a hardness of about 85 HB. As an Al-Si-Cu die casting alloy it is normally used in the as-cast state; no heat-treatment tempers are specified in its data, since high-pressure die cast parts are generally not heat treated due to the risk of blistering from entrapped gas.

Its machinability is excellent; copper improves both mechanical strength and machinability, one of its distinctive advantages. Regarding corrosion, copper-bearing Al-Si-Cu 3xx-series alloys have moderate corrosion resistance (lower than copper-free Al-Si alloys such as 413), so in aggressive environments a protective surface treatment is usually recommended. Its thermal conductivity is 96 W/m·K, useful for heat sinks and electronic housings.

Both are Al-Si-Cu die casting alloys of the 3xx.x series, but they differ in the silicon and copper balance. AlSi11Cu2 (A383, ADC12) has higher silicon (9.5–11.5%) and moderate copper (1.5–3.5%), giving it greater fluidity for thin-wall parts. The 380 (A380, ADC10) has less silicon (~8.5%) and is typically formulated with higher copper (~3.5%); it is the most requested alloy in North America. In practice, A383 is chosen when fluidity and thin-wall castability are the priority.

Yes. At Transformación Puebla we manufacture this alloy from both primary aluminum and secondary (recycled) aluminum. Its tolerance for higher iron levels (≤1.00%) makes it especially compatible with secondary aluminum charges. In addition, our AlSi11 closely resembles a 413 (AlSi12) composition when formulated without copper, and we also manufacture 380-type alloys with higher copper content, tailoring the formulation to your specification.