激光熔凝过程中金属薄膜瞬态电阻的测量  

MEASUREMENT IN TRANSIENT RESISTANCE OF METAL FILMS DURING LASER PULSE HEATING

作　　者：童文辉[1] 杨院生[1] 朱仕学[1] 惠希东[1] 陈晓明[1] 于力[1] 胡壮麒[1] 

机构地区：[1]中国科学院金属研究所,沈阳110016

出　　处：《金属学报》2001年第11期1213-1216,共4页Acta Metallurgica Sinica

基　　金：中国科学院"九五"重大基础研究资助项目KJ951-B1-704

摘　　要：采用瞬态电阻测理方法，对激光表面快速熔凝过程进行了实时跟踪，分析了激光器单脉冲能量、金属薄膜的预热温度等参数对测定结果的影响．结果表明：在快速熔凝过程中金属薄膜的电阻随过程时间呈凸峰状变化，在激光加热周期内，电阻随时间迅速增加，之后随时间的推移又逐渐减小，电阻的减小速度低于增加速度；随着激光功率密度增加，电阻曲线的峰值增大，升温及冷却速度相应增大；随着预热温度的提高，电阻峰值也相应增大，但是样品下表面的热导出率下降，冷却速度下降；当样品下表面的导热能力降低时，样品的电阻曲线峰值有所提高，而在冷却段电阻却明显变化缓慢．The resistance of metal films during laser rapid melting and solidification process (LRMSP) was measured with a transient resistance apparatus which is suitable for measuring between 0 and 500 Omega and the time response of nanosecond. The effects of laser power and preheating temperature on the measuring results were analyzed. The results show that the resistance of aluminum film was increased rapidly and then decreased with time, and the rate of resistance decreasing is slower than that of resistance increasing. The peak value of the measured curve as well as heating and cooling velocities increase with laser power increasing. With preheating temperature enhancing, the peak value also increase, but cooling velocity decreases, resulting from the decrease of heat conductivity of sample lower surface. When the heat-transfer capability of the undersurface of the sample is lower, there is a little increase in resistance peak value, but the change of resistance is slower in the cooling period.

关 键 词：金属薄膜 瞬态电阻测量 激光熔凝 

分 类 号：TG156.99[金属学及工艺—热处理]