保温时间及结晶条件对AZ91D组织和性能的影响  

Effects of Smelting and Crystallization Condition on Microstructure and Properties of AZ91D Alloy

作　　者：张军[1] 罗志华[1] 李培杰[1] 

机构地区：[1]清华大学

出　　处：《特种铸造及有色合金》2006年第2期65-67,共3页Special Casting & Nonferrous Alloys

基　　金：清华大学"985"重点项目(J22001001)

摘　　要：研究了熔炼及结晶条件对AZ91D合金组织和力学能的影响。结果表明,熔体保温时间对铸锭重熔后金属型试样的金相形貌没有影响。铸锭重熔后金属型试样的晶粒尺寸随着保温时间的延长先减小后增加,导致试样抗拉强度和伸长率的先提高后降低。熔体的结晶条件会影响合金的凝固方式。平衡结晶条件下AZ91D组织由基体和Γ相(MG17AL12)组成,在非平衡结晶条件下组织中将出现离异共晶。The effects of smelting and crystallization condition on microstructure and mechanical properties of AZ91D were investigated.The results show that the holding time of melt has little effects on the microstructure of re-melting samples in permanent mold.The grain size of the alloy is firstly decreased and then increased with the increase of the holding time,resulting in the earlier increase and then decease of tensile strength and elongation of the alloy samples.The crystallization condition can affect solidification ways of the alloy.The microstructure of the AZ91D alloy is composed of the matrix phase and γ phase under the condition of equilibrium solidification while the divorced eutectic structure occurs in microstructure under the condition of the non-equilibrium solidification.

关 键 词：结晶条件 保温时间 AZ91D 组织 力学性能 

分 类 号：TG113[金属学及工艺—物理冶金]