Compatibility of High Performance Aluminum-Silicon Alloys with Laser Surface Modification

The goal of the present work is to reduce the environmental impact of car gasoline engines by developing lightweight engine components. The use of light-weight metals such as aluminum results in substantial reductions in CO₂ emissions. Traditionally aluminum alloys have been restricted to low temperature applications because of their poor mechanical properties at elevated temperature. However, novel fabrication methods such as spray forming and rapid solidification have overcome the temperature limitation. Coupled with a surface coating designed to withstand corrosion and wear at elevated temperatures, these high performance alloys may be considered to replace steel-based components in automotive engines. In this work, hypereutectic aluminum-silicon (Al-Si) alloys produced via different fabrication routes were tested for laser coating with a nickel-chromium alloy. Experimental results demonstrating the response of these alloys to laser coating are presented. It was found that the alloy fabrication route had a significant impact on laser compatibility due to the presence of absorbed gases. The results of this work will be translated to prototypes of engine components that will be tested in a test bench.