Be对铸态Al-11Si-0.3Mg合金时效效果的影响  

EFFECT OF Be ON THE AGE-HARDENING CHARACTERISTICS OF AS-CAST Al-11Si-0.3Mg ALLOY

作　　者：王桂青[1] 边秀房[1] 张均艳[1] 

机构地区：[1]山东大学材料液态结构及其遗传性教育部重点实验室

出　　处：《金属学报》2003年第1期43-46,共4页Acta Metallurgica Sinica

基　　金：国家自然科学基金50071028;山东省自然科学基金Z200102资助项目

摘　　要：采用差分扫描量热分析和硬度测定手段,研究了元素Be对铸态Al-11Si-0.3Mg(质量分数,％)合金时效效果的影响.结果表明:在Al-11Si-0.3Mg合金中加入0.25％的Be,铸态时效时硬化相析出速度加快,析出热效应增大,时效硬化效果明显增加.动力学分析表明;亚稳相β＇的析出符合Avrami公式, Be的加入对亚稳相β＇的生长方式参数n影响不大,但明显增大了亚稳相β＇的形核率参数k.金属型铝硅合金铸件中存在很多空位“陷阱”, Be与空位结合阻止空位迁移消失可以解释Be对亚稳相β＇形核率的影响.The effect of minor additions of Be on the age-hardening characteristics of as-cast Al-11Si-0.3Mg (mass fraction, %) alloy was investigated by DSC and Vickes-H analysis. It is shown that the addition of 0.25% (mass fraction). Be can cause faster precipitation and more heat effect of metastable beta' and considerably increases the peak,hardness achieved during as-cast aging. An analysis of the kinetic data shows that metastable beta' precipitation obeys the Avrami equation, and the Be addition has no effect on the growth dependent parameter n, but significantly increases the nuclei density dependent parameter k. There are a large number of vacancy traps within permanent castings of Al-Si alloy. The Be-vacancy binding energy which hinder vacancy sinking at the traps may explain the effect of Be on the nucleation rate and density of metastable beta' during as-cast aging.

关 键 词：铝硅合金 时效硬化 铍 铸造 

分 类 号：TG166.3[金属学及工艺—热处理] TG292[金属学及工艺—金属学]