摘要
本文研究B在Ni基耐热合金瞬时液相扩散连接中的作用机制,采用经过改进的B的核反应产物粒子径迹照相方法和离子探针二次离子照相术及二次离子质谱逐点分析,探明了B在扩散连接区及其附近的分布,对分布与组织性能之间的关系进行了分析研究,发现在高温下经长时间扩散处理之后仍有相当数量的B聚集于基体金属的表层,很难向其“贫B区”长程扩散.此种偏聚是一个非平衡动力学过程,而扩散则是一个多级反应过程.对二次离子质谱逐点分析结果按菲克扩散方程计算得到在1000℃到1130℃温度区间B的扩散系为:D=0.89×10^(-7)cm^2/s～7.12×10^(-7)cm^2/s.
This paper studies the boron's acting mechanism in the transient liquid phase diffusion bonding of nickel base heat resisting alloys. By using an improved particle tracking autoradiography of the products of the boron nuclear reaction, a secondary ion photographic technique of the ion explorer and the point-by-point analysis of the secondary ion mass spectrum, the boron's distribution is verified in the diffusion bonding area or near the area. Furthermore, the relation between the distribution and organic property is discussed. It has been found that there is a little amount of borongathering in the surface of the base metal and it is difficult to diffuse into the poor boron area at high temperatures. This gathering is a non-equilibrium dynamical process, while the diffusion is a process of multilevel reactions. According to the secondary ion point-by-point analytical result and by means of the Fick equation, the boron's diffusivity is calculated when the temperature is between 1000℃ and 1130℃ This diffusivity is D=0.89×10^(-7)～7.12×10^(-7)cm^2/s (t: 1000℃～1130℃).
关键词
硼
液相
扩散
作用机制
diffusion
distribution
secondary ion
diffusivity
