首先用机械合金化方法制备了Al-20%Sn合金粉,然后采用不同的压制、烧结工艺将其制成块状合金;运用X射线衍射仪、扫描电镜等研究了球磨及烧结工艺对Al-20%Sn合金显微组织的影响.结果表明:通过选用高的球磨转速(250 r·min-1)、大的球料比(30∶1)和适当的球磨时间(40 h),可以获得细小锡相均匀弥散分布在铝中的合金粉;当烧结温度低于共晶温度时,锡相保持均匀分布,但当烧结温度超过共晶温度时,锡相明显长大且呈网状分布;高的压制压力(880 MPa)和高的烧结气氛压力(5 MPa)可以有效抑制Al-20%Sn合金在烧结过程中的晶粒长大,保持细小锡相在铝基体中的均匀分布.

First Al-20%Sn alloy powders were prepared by mechanical alloying method,and then the bulk alloy was prepared by different compacting and sintering processes.The effects of milling and sintering processes on the microstructure of Al-20%Sn alloy were characterized by X-ray diffraction and scanning electron microscopy.The results show that microstructure of fine Sn phase distributing homogeneously in Al matrix could be gained by choosing high milling speed (250 r·min-1),large ball-to-powder mass ratio (30∶1) and suitable milling time (40 h).When the sintering temperature is below eutectic temperature,the Sn phase distributed homogeneously in Al matrix.However,when the sintering temperature exceeded the eutectic temperature,coarsening of the Sn phase occured obviously and there was apparent netlike distribution of Sn phase.The grain growth of Al-20%Sn alloy could be restrained effectively by using high compacting pressure and sintering pressure in sintering process,and the homogeneous distribution of fine Sn phase in Al matrix was still kept.