研究固溶时效处理对粉末热挤压法制备的体积分数15%的硼酸镁晶须增强6061铝基复合材料的显微组织及力学性能的影响.结果表明:Mg2B2O5w在复合材料基体中以短杆状和团聚体形式存在.经520℃,50 min固溶和170℃,10 h时效处理后Mg2Si相弥散分布,其平均晶粒尺寸长大,从处理前的32nm增加到处理后的95 nm,时效开始时间较基体合金提前;时效后复合材料屈服强度和抗拉强度分别为254、307 MPa,增幅达45.1%和31.2%,但延伸率降低40%.
The effect of solid solution aging treatment on the microstructure and mechanical properties of hot extrusion 6061 aluminum matrix composites reinforced with magnesium borate whisker of 15 % volume fraction was studied.The results show that the Mg2B2O5w exist mostly in the composites matrix in the form of short rods and aggregate.After solution treatment at 520℃ for 50 min,and following aging treatment at 170 ℃ for 10 h,the Mg2Si phase have an dispersive distribution,and its average grain size increase from 32 nm before aging treatment to 95 nm after aging treatment.Compared with the matrix alloy,the start time of aging of composites is advance.After aging treatment,the yield strength and tensile strength of composites is increased to the maximum value of 254,307 MPa,and the increment is 45.1% and 31.2%,respectively,but the elongation rate is decreased by 40%.