快速凝固法制备Mg-Al-Ca合金薄带  

Preparation of Mg-Al-Ca Ribbons by Melt-spinning

作　　者：华旻[1] 马立群[1] 丁毅[1] 张振忠[1] 

机构地区：[1]南京工业大学材料科学与工程学院

出　　处：《特种铸造及有色合金》2007年第8期619-622,共4页Special Casting & Nonferrous Alloys

基　　金：中国人民解放军武器装备重点基金项目(6140502);南京工业大学引进人才科研启动基金项目(51303027)

摘　　要：通过单辊快淬法制备了Mg-8.2Al-4.7Ca合金薄带,采用XRF、XRD、金相显微分析、显微硬度测量等分析方法研究了其凝固组织及相结构,以及转速对镁合金条带厚度和显微硬度的影响。研究结果表明,急冷快速凝固条件下,合金形成非晶相+细小hcp-Mg(Al,Ca)相;镁合金薄带显微组织沿厚度方向分为近辊面细晶区、内部柱状晶和自由面粗晶区;随着辊速的提高,晶粒不断细化,薄带的硬度不断提高。晶粒细化是显微硬度提高的主要原因。The solidification structure and phase constituent of Mg-8.2Al-4.7Ca alloy ribbons prepared by melt-spinning have been observed by XRF,XRD, optical observation and micro-hardness measurements, meanwhile, the effects of rotating speed of the single-roller on the thickness and micro-hardness of the Mg alloy ribbons have been approached. The results indicate that the melt-spinning alloy ribbons are composed of amorphous phase and fine hcp-Mg(Al,Ca) phase, which is different from that of conventionally solidified alloy ribbons. It can be observed from the cross section of the ribbon that three distinct zones appears in the microstructure: fine equiaxed grain size close to the copper roller, columnar zone and coarse equiaxed grain zone close to the free surface. With the increase of rolling speed, the micro-hardness of the alloy ribbons can be increased, which is attributed to the refinement of the grain size.

关 键 词：快速凝固 Mg-Al-Ca合金 显微组织 显微硬度 

分 类 号：TG27[金属学及工艺—铸造]