AZ91HP非连续析出的组织转变特点  

Characteristic of non-continuous precipitated phase in AZ91HP

作　　者：王越[1] 吴伟[1] 刘正[1] 宋德仁[2] 李锋[1] 刘重阳 

机构地区：[1]沈阳工业大学材料科学与工程学院,辽宁 沈阳 110023 [2]沈阳化工学校,辽宁 沈阳 110023

出　　处：《沈阳工业大学学报》2000年第6期467-470,共4页Journal of Shenyang University of Technology

摘　　要：ＡＺ９１ＨＰ压铸试样在加热至 ４１５ ℃、保温 ８ ｈ并淬火之后，晶界上离异共晶的粗块状β－Ａｌ１２Ｍｇ１７相将溶入基体，形成过饱和的α－Ｍｇ固溶体α－Ｍｇ固溶体在人工时效过程中，将发生β－ Ａｌ１２Ｍｇ１７的非连续和连续的沉淀析出。非连续析出的β－Ａｌ１２Ｍｇ１７相在时间和数量上分别先于和大于连续析出的β－Ａｌ１２Ｍｇ１７相，其形态和数量都随时效时间变化，对合金的性能影响较大。金相组织观察显示，非连续析出的β－Ａｌ１２Ｍｇ１７相首先在晶界形核，开始时呈颗粒状，随后进入块和胞状共存阶段，最后块状的β－Ａｌ１２Ｍｇ１７相消失，胞状β－Ａｌ１２Ｍｇ１７相不断地向晶内蔓延长大。伴随着β－Ａｌ１２Ｍｇ１７相的析出与形态转变过程，ＡＺ９１ＨＰ性能也随之变化，显示了明显的时效硬化特征。The divorce associate coarse β-Al12Mg17 distributed along the grain boundary will dissolved in the base to form supersaturated solid solution of α- Mg when AZ91HP die casting was heated to 415 ℃ for 8 hours and then quenched. The β - Al12Mg17 will precipitated as continuous and non-continuous form during artificial aging. Non - continuous β - Al12 Mg17 precipitates earlier and more than continuous β -Al12Mg17. The morphology and amount of non- continuous β-Al12Mg17 changed with aging time and had a great effect on the properties of the alloy. The microstructure observation shown that nucleation of non - continuous β - Al12 Mg17 precipitated as the granules along the grain boundaries first, and then it grew up and changed the morphology into the mixture of block and cell, finally the blocks of β - Al12 Mg17 disappeared and the cells extended into the crystal grains. Along with the course of precipitations its morphology changed and the mechanical properties of AZ91HP were also changed and shown obvious precipitation hardening.

关 键 词：镁合金 热处理 机械性能 AZ01HP 压铸 

分 类 号：TG146.22[一般工业技术—材料科学与工程]