Aluminum alloy powder formulations with silicon additions for mechanical property improvements
The mechanical properties and thermal resistance of a sintered component made from an Al—Cu—Mg—Sn alloy powder metal mixture can be improved by doping the Al—Cu—Mg—Sn alloy powder metal mixture with a silicon addition. Silicon is added as a constituent to the Al—Cu—Mg—Sn alloy powder metal mixture. The Al—Cu—Mg—Sn alloy powder metal mixture is compacted to form a preform and the preform is sintered to form the sintered component.
1. A method of improving the mechanical properties of a sintered component made from an Al—Cu—Mg—Sn alloy powder metal mixture with a silicon addition, the method comprising:
adding silicon as a constituent to the Al—Cu—Mg—Sn alloy powder metal mixture wherein the weight percent of silicon in the Al—Cu—Mg—Sn alloy powder metal mixture with the silicon addition is in a range of 0.05 to 0.8 weight percent;
compacting the Al—Cu—Mg—Sn alloy powder metal mixture to form a preform; and
sintering the preform to form the sintered component;
wherein the silicon is provided as an Al-12Si master alloy powder metal having a eutectic temperature of approximately 577° C. at which the Al-12Si master alloy powder metal melts to form a liquid phase and wherein the sintering occurs at a sintering temperature above the eutectic temperature.
2. The method of claim 1 , wherein the step of sintering occurs in an atmosphere of nitrogen.
3. The method of claim 1 , wherein, at the start of the sintering step, the liquid phase from the Al-12Si master alloy powder metal forms and is transported between the un-sintered particles of the Al—Cu—Mg—Sn alloy powder metal mixture via capillary force.
4. The method of claim 3 , wherein, the silicon in the liquid phase from the Al-12Si master alloy powder metal diffuses from the liquid phase into other solid aluminum grains in the Al—Cu—Mg—Sn alloy powder metal mixture.
5. The method of claim 1 , wherein the weight percent of silicon in the Al—Cu—Mg—Sn alloy powder metal mixture is in a range of 0.1 to 0.3 weight percent to improve thermal stability of the mechanical properties of the sintered component.
6. A method of improving the mechanical properties of a sintered component made from an Al—Cu—Mg—Sn alloy powder metal mixture with a silicon addition, the method comprising:
adding silicon as a constituent to the Al—Cu—Mg—Sn alloy powder metal mixture wherein the weight percent of silicon in the Al—Cu—Mg—Sn alloy powder metal mixture with the silicon addition is in a range of 0.05 to 0.8 weight percent, wherein the Al—Cu—Mg—Sn alloy powder metal mixture comprises:
an atomized aluminum powder metal in which the aluminum powder is prealloyed with a member selected from the group consisting of iron separately, nickel separately, and iron and nickel together;
a first master alloy powder metal comprising aluminum and copper;
a second master alloy powder metal comprising aluminum and silicon;
a magnesium elemental powder metal; and
a tin elemental powder metal;
compacting the Al—Cu—Mg—Sn alloy powder metal mixture to form a preform; and
sintering the preform to form the sintered component.
7. The method of claim 6 , the second master alloy comprising aluminum and silicon is an Al-12Si master alloy.
8. The method of claim 6 , wherein the first master alloy powder metal comprising aluminum and copper is an Al-50Cu master alloy and wherein the second master alloy comprising aluminum and silicon is an Al-12Si master alloy.
9. The method of claim 6 , wherein Al—Cu—Mg—Sn alloy powder metal mixture includes 2.3 weight percent copper, 1.6 weight percent magnesium, 0.2 weight percent tin, and 0.2 weight percent silicon.
10. The method of claim 9 , wherein the Al—Cu—Mg—Sn alloy powder metal mixture includes 1.0 weight percent iron.
11. The method of claim 9 , wherein the Al—Cu—Mg—Sn alloy powder metal mixture includes 1.0 weight percent nickel.
12. The method of claim 9 , wherein the Al—Cu—Mg—Sn alloy powder metal mixture includes 1.0 weight percent iron and 1.0 weight percent nickel.
13. The method of claim 6 , wherein the Al—Cu—Mg—Sn alloy powder metal mixture includes 1.5 weight percent admixed Licowax C powder.
14. The method of claim 6 , wherein the weight percent of silicon in the Al—Cu—Mg—Sn alloy powder metal mixture is in a range of 0.1 to 0.3 weight percent to improve thermal stability of the mechanical properties of the sintered component.
15. The method of claim 14 , wherein the weight percent of silicon in Al—Cu—Mg—Sn alloy powder metal mixture is 0.2 weight percent.