The effect of spray-formed Al22Si coating on wear resistance performance

The future trends of modern automobiles will apply lightweight material to boost fuel economy and energy efficiency. While the spray-formed Al22Si coatings are suitable candidates for improving the wear resistance of the lightweight materials. The morphology of the wear tracks was compared between spray-formed Al22Si and cast iron, and the relationship between the wear loss and the microscopic wear mechanisms was also discussed. The result shows that the wear resistance performance of the spray-formed Al22Si alloy was better than that of cast iron, and its wear loss presented an approximately linear relationship with the sliding distance. It was also shown that damage within the spray-formed Al22Si occurred in two stages. Initially, the spray-formed Al22Si alloy was extremely worn due to an abrasive action on the sharp particles and the fracture of the larger particles. Once the sharp edges of the abrasive became blunt with the wear progress, the degree of wear and tear decreased dramatically. In the stable wear stage, a small number of tiny particles are gradually worn out that can reduce the asperity contact and reduce the friction and wear. The wear resistance of the spray-formed Al22Si improved as the number and homogeneous distribution of the hard particles increased and their sizes decreased. The present study shows that spray-formed Al22Si not only reduces the automotive weight, but also enhances the life of the engine cylinder more than cast iron.