喷射沉积Al-Zn-Mg-Cu合金挤压杯形件组织和性能研究

Microstructure and properties of spray deposited Al-Zn-Mg-Cu alloy extruded cup-shaped part

以喷射沉积Al-Zn-Mg-Cu合金为试验材料,采用热挤压和环形通道转角挤压工艺制备杯形件,并进行固溶时效处理,研究其对喷射沉积Al-Zn-Mg-Cu合金组织和力学性能的影响。结果表明:沉积态合金晶粒呈等轴状,尺寸约为20~30μm;MgZn_(2)相沿晶界析出形成连续网状,在晶粒内部析出呈球、棒状。经热挤压后,细小孔隙闭合,晶界分布的网状MgZn_(2)相破碎,抗拉强度提高至437 MPa。经环形通道转角挤压,杯形件壁部形成定向拉长晶粒组成的纤维组织,伸长率提高至14.5%。固溶时效处理进一步提高了杯形件的力学性能,抗拉强度达700 MPa,屈服强度达654 MPa,伸长率达7.3%。

Spray deposited Al-Zn-Mg-Cu aluminum alloy was used as the experimental material.The cup-shaped part wasprepared by hot extrusion and annular channel angular extrusion process,and subsequently subjected to solid solution and agingheat treatment process.The effect of the process on the microstructure and mechanical properties of spray deposited Al-Zn-Mg-Cu alloy was studied.The results show that the spray deposited alloy has uniform equiaxed grains with a grain size of about 20-30μm.The MgZn_(2) phases precipitate along the grain boundary to form a continuous network,and spherical and rod-shaped phasesprecipitate in the grain.Hot extrusion closes the pores of the spray deposited alloy,breaks the network MgZn_(2) phases,and theimprove tensile strength up to 437 MPa for the spray deposited alloy.After the annular channel angular extrusion,the fibrousstructure composed of directionally elongated grains is formed on the wall of the cup-shaped part,and the elongation of the alloyis increased to 14.5%.Solution and aging heat treatment further improve the mechanical properties of cup-shaped part,with atensile strength of 700 MPa,a yield strength of 654 MPa and an elongation of 7.3%.