物理变质处理对消失模铸造AZ91合金组织及力学性能的影响  

Effect of Physical Refining on Microstructure and Mechanical Properties of Lost Foam Casting AZ91 Alloy

作　　者：田学锋[1] 樊自田[2] 黄乃瑜[2] 

机构地区：[1]东北大学材料与冶金学院,辽宁沈阳110004 [2]华中科技大学材料科学与工程学院,湖北武汉430074

出　　处：《铸造》2010年第6期573-577,共5页Foundry

基　　金：国家自然科学基金资助项目(50275058)

摘　　要：在消失模铸造条件下,分别采用机械振动及熔体混合处理对AZ91合金的组织形貌和力学性能进行了研究,并分析了凝固过程中细化晶粒的机制。试验结果表明:采用机械振动及熔体混合处理都能显著地细化消失模铸造AZ91合金的组织,并显著提高力学性能。当机械振动激振力为1.5kN时,AZ91合金综合力学性能最优,其主要通过增大过冷度、枝晶臂熔断等作用细化组织。熔体混合处理其效果强于传统的熔体高温处理,熔体混合处理通过在混合液体中产生更多的核胚以增加形核位置,来细化枝晶组织。The effects of mechanical vibration and melt mixing process on the microstructure morphology and mechanical properties of lost foam casting （LFC） AZ91 alloy were investigated respectively. The refining mechanisms of the casting alloy microstructure under two processes were also analyzed. The results show that mechanical vibration and melt mixing process both could produce finer dendrite in the AZ91 alloy, and strongly improved the mechanical properties. The value of mechanical properties of the AZ91 alloy was optimal when the casting was fabricated under the 1.5 kN mechanical vibrations. The mechanical vibration resulted in refining effect by improving undercooling degree and melting off dendritic arms, etc. The melt mixing process resulted in refinement by providing more nucleate sites in the mixed melt and its refining effect is superior to the traditional high-temperature treatment.

关 键 词：机械振动 熔体混合处理 AZ91合金 消失模铸造 微观组织 力学性能 

分 类 号：TG249.6[金属学及工艺—铸造]