机械合金化制备Mg-Cu非晶合金粉末的机理研究

Study of the Mechanism of Mechanical Alloying for Mg-Cu Amorphous Alloy Formation

采用XRD和TEM研究了MgCu2和Mg58Cu42混合粉末在机械合金化过程中的结构变化。结果表明:Mg、Cu粉末在机械合金化过程中是互溶的,机械合金化可以大大提高它们之间的固溶度;球磨过程中,Mg原子逐步溶入Cu基体中,形成Mg在Cu中的过饱和固溶体;固溶体的变形能量积聚到很大时,发生固溶体晶体结构的失稳,最后形成非晶态合金。在相同的球料比的条件下,提高球磨转速,可以大大促进非晶化的形成过程,缩短非晶形成的时间。

The structure of the MgCu_ 2 and Mg_ 58Cu_ 42 amorphous powders, prepared by mechanical alloying after different milling times, had been studied by XRD and TEM in this paper. The results showed that Mg and Cu powders could dissolve into each other and the dissolution degree became larger after milling. During the milling process, Mg powders firstly dissolved into the gap of Cu crystal lattice and the solid solution with Mg supersaturation was formed. Then, the energy of supersaturation became large enough to break its stability, and the amorphous alloy was obtained at the end. At the same weight ratio of ball-to-powder, enhancing the velocity of milling could accelerate the amorphization process.