【摘要】 采用铸造接触反应法制备Al-TiC中间合金,EPMA和XRD分析显示,反应温度和保温时间是TiC颗粒原位合成的重要工艺参数,基于热力学计算和动力学分析探讨了原位TiC颗粒的形成机制。在AZ91镁合金熔体中加入0.3%的Al-10%TiC中间合金可明显细化晶粒尺寸,由基体合金的107μm降至57μm,降低幅度约为47%。晶粒细化机制可归结为TiC颗粒作为初生α-Mg的异质晶核。更多还原

【Abstract】 The Al-TiC master alloy concerned was prepared by casting contact reaction method,and analyzed the results by EPMA and XRD.The reaction temperature and holding time were significant processing parameters to TiC particles of in situ synthesized.The study of formation mechanism of in situ TiC particles was based on thermodynamics calculation and kinetic analysis.After adding 0.3wt% Al-10%TiC master alloy in melted AZ91 magnesium alloy,the grains were obviously refined,whose size was decreased from 107 μm(matrix alloy) to 57 μm and the reduced extent was about 47%.The mechanism of grain refinement was ascribed to the TiC particles acting as heterogeneous crystal nucleus of primary α-Mg.更多还原