Study On Heat Treatment Technology Of Al-10Si Alloy By Additive Manufacturing Method

This subject is part of the research project of aviation joint fund of Liaoning science and technology department.Study on the optimization problem of additive manufacturing method used in Shenyang Aircraft Industry Group Co.,Ltd.aluminum alloy parts manufacturing sample system of heat treatment,heat treatment of Al-10Si alloy by different systems of additive manufacturing method of preparation,to analyze the effect of heat treatment on microstructure and properties of Al-10Si alloy,provide technical support for the development of additive manufacturing method aluminum alloy products heat treatment technology.This paper mainly studies two aspects:(1)Study on micro structure and properties of Al-10Si alloy by additive manufacturing method.(2)Effect of heat treatment Technology on microstructure and mechanical properties of Al-10Si alloy by additive manufacturing method.The results show that:(1)The typical microstructure parallel to the construction direction is the molten pool like fish scale,its growth direction is parallel to the direction of heat transfer,the grain near the bottom of the molten pool is fine,and coarse grain is far from the bottom of the molten pool,the eutectic structure in the grains is "tubular" and the nanometer Si particles are small and uniform.(2)The tensile strength and elongation of Al-10Si alloy samples perpendicular to the construction direction are respectively 487.5MPa and 9.0%,the tensile strength and elongation in parallel with the construction direction are respectively 490.0MPa and 7.0%.(3)In the annealing process that Al-10Si alloy samples are at a temperature of at 170-300? for 2 hours,when the temperature is below 200?,the tensile strength of each direction varies little compared with the original sample,the fracture strength of samples parallel to the construction direction is between 460.0MPa and 485.0MPa,and the fracture strength of samples perpendicular to the construction direction is between 495.0MPa and 502.5MPa.With increasing the annealing temperature,the tensile strength decreased.When the annealing temperature is 300?,the fracture strength of samples parallel to the construction direction is reduced to 292.5MPa and the fracture strength of samples perpendicular to the construction direction is reduced to 310.0MPa.(4)In the annealing process that A1-10Si alloy samples are at the temperature of 170-300? for 2 hours,when the temperature is below 200?,the elongation of each direction varies little compared with the original sample.When the temperature is at 200? for 2 hours,the elongation of each direction of the sample is the lowest,the elongation of samples parallel to the construction direction is reduced to 8.0%and the elongation of samples perpendicular to the construction direction is reduced to 5.2%.With increasing the annealing temperature,the elongation of samples increased.When the annealing temperature is 300?,the elongation of samples parallel to the construction direction is reduced to 15.6%and the elongation of samples perpendicular to the construction direction is reduced to 11.9%.(5)In the annealing process that A1-10Si alloy samples are at the temperature of 280? for 2-8 hours,when the holding time is below 4 hours,with increasing the holding time,the tensile strength of samples were significantly decreased.When the holding time is 4 hours,the tensile strength of samples parallel to the construction direction is reduced to 279.3MPa and the tensile strength of samples perpendicular to the construction direction is reduced to 301.1 MPa.When the holding time is more than 4 hours,the tensile strength of each direction samples is basically unchanged.(6)In the annealing process that A1-10Si alloy samples are at the temperature of 280? for 2-8 hours,when the holding time is below 4 hours,with increasing the holding time,the elongation of each direction samples were significantly increased.When the holding time is 4 hours,the elongation of samples parallel to the construction direction is rose to 38.1%and the elongation of samples perpendicular to the construction direction is rose to 27.6%.When the holding time is more than 4 hours,the elongation of each direction samples is basically unchanged.