SHS法制备Al_3Ti/Al复合材料的研究

Al_3Ti/Al Composites Prepared by SHS

介绍了高熔点化合物颗粒增强的铝基复合材料的一种先进制备方法 ,即自蔓延高温合成法 (SHS法 ) ,并以Al3Ti/ Al为例进行了实验研究。结果表明 ,将 Ti粉与 Al粉混合 ,在铝合金液中进行自蔓延高温合成 ,可有效地控制 Al3Ti的形态。其中 Al∶Ti比是控制 Al3Ti形态的关键参数。当 Al∶Ti比远小于理论化学计量比 3∶ 1时 ,获得针状 Al3Ti组织。而当该比值等于或大于 3∶ 1时则获得块状 Al3Ti组织 ,其分布也更均匀。但该比值太大 (大于约3.75∶ 1)时 ,则因 Al粉升温和熔化吸热 ,将使得自蔓延合成反应终止。

An advanced method of producing Al 3Ti/Al composites, self propagating high temperature synthesis (SHS) in an Al melt, is described. The mole ratio of Al/Ti in the starting powder mixture is an important parameter for that controls the microstructure of the Al 3Ti compound produced by SHS. When Al/Ti is much smaller than 3/1(the stoichiometric ratio), large needle like Al 3Ti structures will be produced. When Al/Ti is close to or larger than this value, the more favorable homogeneously distributed blocky Al 3Ti will be obtained. But if Al/Ti ratio is larger than 3 75/1, the SHS process will stop because more heat is consumed for heating up and melting the Al powder.