球磨工艺对Mg2B2O5w/6061Al基复合材料微观组织演变及力学性能的影响

Effect of Ball Milling on Microstructure and Mechanical Properties of Mg_2B_2O_5w/6061Al Matrix Composites

采用粉末热挤压法制备了硼酸镁晶须增强铝基复合材料,对球磨工艺参数、粉末特性及热挤压态复合材料间的相互关系进行了研究。研究结果表明,在球磨过程中,增强体晶须的添加促进了基体合金的变形,加快了铝粉颗粒的焊合与断裂过程的发生。在球磨过程中,经过适当时间的高速球磨后,铝合金基体晶粒尺寸减小,增强体晶须在基体中的分布得到显著改善,从而使热挤压态复合材料力学性能得到大幅度的提高。

Mg_2B_2O_5 wisker/6061（AlMg_2B_2O_5w/6061Al） matrix composites were fabricated through the powder metallurgy（PM） technique. The relationship among the parameters of ball milling, powder characteristics, and mechanical properties of the hot extruded composites was investigated. The results show that the reinforcement whiskers accelerate the milling process by increasing the matrix deformation and enhancing the welding and the fracture of particles. Furthermore, the mixing process is modified by a higher milling speed and suitable milling time, which result in reduced crystalline size, improved homogeneity of the whisker distribution, as well as enhanced tensile strength of the hot extruded composites.