Investigation of the Heat Treatment Regimes on the Structure and Microhardness of Laser Direct Energy Deposition Aluminum Alloy AlSi10Mg

This study investigates the influence of various heat treatment regimes on the structure and microhardness of the aluminum alloy AlSi10Mg processed by the L-DED method. The study considers heat treatment regimes for solid solution in the temperature range of 500-540 degrees C with holding times of 30-120 min, as well as artificial aging regimes in the temperature range of 160-190 degrees C with holding times of 4-8 h. As a result of studying the structure and mechanical properties of the heat-treated samples, it became clear that the optimal regime can be considered the regime of 500 degrees C for 30 min followed by 190 degrees C for 6 h. This regime leads to the formation of a uniform structure with the breakage of the eutectic network into separate spherical silicon inclusions. The microhardness in this case is 90 HV, which is 55% higher than the initial state. Using TEM, it was established that the reason for the increase in hardness is the formation of nanoscale inclusions beta '' (Mg5Si6).