Mechanical properties of cast aluminum alloys in a wide temperature range

Environmental and emission control regulations for automobiles are imposed to reduce the carbon dioxide imprint and fuel consumption by engines, which transform chemical energy of fuels into mechanical. Most of the energy transforms into heat and may affect the mechanical properties of the alloys used in power train parts. Aluminum alloys can be affected by the increase in the operating temperature; therefore, the interest in developing alloys able to sustain stringer mechanical demands at higher temperatures. This work reports the mechanical properties of different aluminum alloys used in the manufacture of power-train automotive parts. The alloys were cast in wedge shape ingots that affect the size and shape of microstructural constituents. Tensile samples were machined from bars with different degrees of microstructural refining and were heat treated at times and temperatures that depended on their chemical composition. The mechanical properties were measured after holding the heat treated samples for 200 hours at temperatures ranging from 25 to 300°C. It was found that microstructural refining enhances the properties, independently on the alloying elements. The material alloyed with copper exhibited better properties than Al-Si alloys; increment in the content of Cu in Al-Si-Mg alloys enhanced the mechanical properties above room temperature.