真空冷喷涂铜颗粒加速特性数值研究  

Numerical Study on Accelerating Characteristics of Copper Particles in Vacuum Cold Spraying Process

作　　者：郑建新[1] 金耀辉[1] 刘传绍[1] 

机构地区：[1]河南理工大学,焦作454003

出　　处：《表面技术》2013年第1期5-8,共4页Surface Technology

基　　金：无锡市国际科技合作计划项目(CZE00902)

摘　　要：基于Fluent气固两相流数值模拟,研究真空冷喷涂铜颗粒的加速特性,分析了环境压力、喷涂距离、入口总温和颗粒粒径等参数对真空环境下颗粒撞击速度的影响。结果表明:环境压力是决定颗粒撞击速度的关键因素,随环境压力的变化,小直径颗粒(dp≤1μm)撞击速度的变化曲线呈抛物线状态,但大直径颗粒无显著变化;采用合适的喷涂距离,才能获得最大的颗粒撞击速度;增加入口总温可提高小直径颗粒的撞击速度,但对大直径颗粒无明显加速效果;真空冷喷涂颗粒的尺寸可从微米级减小至亚微米级,但过小的颗粒仍难达到足够高的撞击速度。The accelerating characteristics of copper particles in the process of vacuum cold spraying were investigated based on numerical simulation of gas-particle two phase flow with Fluent, and the influences of ambient pressure, stand-off distance （ SoD）, inlet temperature and diameter of particles on particle impact velocities were analyzed. The results indicate that the ambient pressure is the key factor affecting the particle impact velocities, and the velocity curve for the small particles with diameters smaller than 1 ~m is parabolic with the change of the ambient pressure, while no significant change for the big particles ; The higher impact velocities may be obtained with suitable SoD ; The impact velocities increase with the increment of inlet temperatures for the small particles, but which does not happen for the big particles with the same conditions; The minimum particle size can be reduced from micron size to submicron size in the process of vacuum cold spraying, but too smaller particles cannot obtain enough high impact velocities so as to be deposited.

关 键 词：真空冷喷涂 加速特性 颗粒撞击速度 气固两相流 数值模拟 

分 类 号：TG174.442[金属学及工艺—金属表面处理] TQ02[金属学及工艺—金属学]