Analysis of Structure and Microhardness AlSi5Cu2 and AlSi10Cu2 Cast Alloys Subjected to Electron Beam Surface Melting

The research deals with the modification of AlSi5Cu2and AlSi10Cu2 alloy surfaces by the method of electron beam processing. It is established that the irradiation of the alloys by concentrated energy flow is accompanied by the increase in microhardness and covering the surface defects. Due to a great temperature difference between two media the surface melts at a superhigh rate and crystallizes again, because of it a grain size decreases resulting in the increase in microhardness. The arising tensile stresses contribute to the covering of the surface defects.