Cu-2.0wt%Be合金中晶界析出相对弹性性能的影响

Effect of Grain Boundary Precipitation on Elastic Properties of Cu-2.0wt%Be Alloy

摘要:

本文对Cu-2.0wt%Be合金晶界处不连续析出相的形貌及其与热处理参数之间的关系进行了研究,利用正交试验设计的方法选取热处理参数,制备微观结构差距较大的样品,从中筛选所需样品研究了晶界反应物对滞弹性行为的影响。不连续析出相主要存在于晶界处,主要由γ相和α基体相组成。根据极差分析结果,影响晶界反应量的热处理参数主要为二级时效温度,其次为一级时效时间和二级时效时间。滞弹性行为分析表明,晶界反应量对样品加载过程中的变形量影响较大,这是由于不连续析出形成的γ相与基体为非共格关系,在γ相周围存在原子无序区域,位错在此处的湮灭引起原子重排,因此晶体产生滑移,造成合金塑性变形。而无晶界反应物的晶界两侧交错排列着γ’相,位错容易在此处塞积,阻碍晶体滑移。

Abstract:

In this paper, the morphology of discontinuous precipitates at the grain boundary of Cu-2.0wt% Be alloy and the relationship between the discontinuous precipitates and heat treatment parameters were studied. The heat treatment parameters were selected by orthogonal experimental design, and the samples with a large difference in microstructure were prepared. The discontinuous precipitates mainly exist at the grain boundary and are mainly composed of γ phase and α matrix phase. According to the results of range analysis, the main heat treatment parameters affecting grain boundary reaction amount are secondary aging temperature, followed by primary aging time and secondary aging time. The analysis of anelastic behavior shows that the grain boundary reaction amount has a great influence on the deformation of the sample during loading. This is due to the non coherent relationship between the γ phase formed by discontinuous precipitation and the matrix. There is a disordered region around the γ phase, where the annihilation of dislocations causes the rearrangement of atoms, resulting in crystal slip and plastic deformation of the alloy. However, the two sides of the grain boundary without boundary reactants are crisscrossed with γ "phase, where dislocations are easy to pile up and hinder the crystal sliding.