Zn-Al合金的相变与尺寸稳定性研究

来源期刊：中南大学学报(自然科学版)1992年第6期

论文作者：田荣璋 王志远

文章页码：712 - 718

关键词：锌合金；相变；尺寸稳定性，脱溶；共析分解；四相反应；相变应力

Key words：zinc alloys, phase transformation, dimension stability, precipitation, eutectoid reaction; four-phase reaction; phase transformation stress

摘    要：

运用X射线衍射，长度测量、金相分析和理论计算等方法，研究了Zn -Al二元合金中富铝α相、富锌口相的脱溶和共析分解(β→α+η)以及Zn-Al-Cu三元系中四相反应α+ε→T′+η的规律及其对合金尺寸稳定性的影响．α相和η相的脱溶以及β相的共析分解可造成合金体积的收缩，而含铜η相的脱溶和四相反应则可造成合金体积的膨胀．计算表明，四相反应的平衡方程式可写成如下形式：

22α+ 78ε= 34 T′+ 66η

Abstract:

The rule of precipitation of rich-aluminium a phase and rich-zine 77 phase and decomposition of entectoid β→α+η and four-phase reaction α+ε→T′+η in Zn-Al Cu system is examined with X-ray diffraction, theory calculation, linear measurement and metal phase analysis. The effect of these phase transformations on dimension stability of zinc alloys is investigated. Precipitation of α and η phases and eutectoid reaction of β may cause volume contract.ion, while four-phase reaction and precipitation of η phase containing copper lead to serious volume expansion. Theory calculation shows that equilibrium equation of four-phase reaction can be expressed as follows:

22α+ 78ε= 34 T′+ 66η