球磨工艺对粉末热挤压制备铝基复合材料力学性能的影响

Influence of ball milling processes on mechanical properties of Al-matrix composites prepared with powder hot extrusion

采用粉末热挤压工艺制备体积分数10%的硼酸镁晶须增强铝基复合材料,研究球磨工艺参数即球磨速度、球磨时间对晶须分布均匀性及复合材料力学性能的影响.结果表明:球磨速度和球磨时间是影响铝基复合材料力学性能的重要因素,球磨速度过快不利于后期材料的热挤压成形,随着球磨时间的延长,晶须的折断现象严重.球磨速度150r/min、球磨时间10h、挤压比25∶1的条件下制备的挤压态复合材料硼酸镁晶须分布均匀,材料的抗拉强度为230MPa,延伸率7%.

The 10 ％-volume-fraction Mg2 B2O5w/6061Al composite was fabricated with powder hot extrusion process,the influence of speed and time of milling on uniformity of Mg2 B2 O5 whisker distribution and mechanical properties of the composite was studied.The result showed that milling speed and milling time were the two important effective factors on the properties of composite.It would be unfavorable for the hot extrusion forming of the material later if the milling speed was excessive large.The amount of broken whisker was proportional to the ball milling time.After milling at speed of 150 r/min for 10 h and with extrusion ratio of 25 ∶ 1,the whisker distributed homogeneously in the matrix,the tensile strength and elongation of hot extruded composite were 230 MPa and 7 ％,separately.