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通过预球磨和低温球磨原位制备了尺寸约300nm的TiCp与铝的复合颗粒,采用搅拌铸造法将复合颗粒与镁合金复合,制备了TiCp/AZ91复合材料,并研究了材料的微观组织和性能。结果表明,通过低温球磨可以原位生成TiCp/Al复合颗粒,搅拌能够将复合颗粒搅入镁合金中。TiCp体积分数低时(3%),制备的复合材料中TiCp分布比较均匀;体积分数较高时,TiCp沿晶界分布倾向增大;当体积分数达到7%时,TiCp主要沿晶界分布。性能测试结果表明,复合材料的室温抗拉强度达287.72MPa,弹性模量达69.23GPa。200℃下抗拉强度达245.49MPa,弹性模量达到51.32GPa。复合材料的蠕变性能为:170℃和55MPa以及175℃和60MPa下100h总蠕变量分别为0.182%和0.191%。细小的增强颗粒对位错和晶粒边界的钉轧作用是导致复合材料具有良好的高温拉伸和蠕变性能的原因。
The TiCp / Al composite particles with the size of about 300 nm were prepared by pre-ball milling and low-temperature ball milling in situ. TiCp / AZ91 composites were prepared by mixing and casting the composite particles with magnesium alloy. The microstructure and properties . The results show that TiCp / Al composite particles can be formed in situ by low temperature ball milling, and the composite particles can be stirred into magnesium alloy by stirring. When TiCp volume fraction is low (3%), the distribution of TiCp in the composites is uniform. When the volume fraction is high, TiCp tends to increase along the grain boundaries. When the volume fraction reaches 7%, TiCp distributes along the grain boundaries. The results of performance test show that the tensile strength of the composites reaches 287.72MPa and the elastic modulus reaches 69.23GPa. The tensile strength at 200 ℃ reached 245.49MPa and the elastic modulus reached 51.32GPa. The creep properties of the composites were as follows: the total creep of 100h at 170 ℃ and 55MPa and at 175 ℃ and 60MPa were 0.182% and 0.191% respectively. The pinning effect of the fine particles on the dislocations and grain boundaries is the reason that the composite has good high temperature tensile and creep properties.