摘要
利用文献所介绍的原位法并加以改进 ,测定了铝合金表面呈固态和液态时对激光的吸收率。实验结果表明 ,试样的表面状况对激光吸收率有重要影响 ,激光功率对吸收率的影响甚小 ,但对表面涂黑的试样 ,激光功率过高会使涂层烧损而降低吸收率。当试样表面出现熔池时 ,所测得的吸收率是激光斑点中液态表面和固态表面的综合平均值 ,真实的液态吸收率需用实测与数值模拟相结合的方法求取。当激光入射角在 0°～ 45°范围时 ,无论是固态试样还是出现熔池 ,其吸收率均随入射角的增大而线性增加。文中对实测数据的回归处理方法亦做了改进 ,先将较复杂的曲线方程转换成直线方程 ,然后进行线性回归处理。
An in-situ technique was used to determine the laser absorptivity of solid and liquid surfaces of Al-alloys. The experimental results show that the surface condition of the sample is the most important factor affecting the laser absorptivity. Usually, the absorptivity increases a little with the increase in laser power. But if the laser power is too high, the absorptivity of blacked samples will be decreased because of burnout of blacking layer. When melting pool emerges on the surface of sample, the measured laser absorptivity is an ensemble average value for liquid and solid zones within the area of laser spot, and the real absorptivity of liquid surface will be determined by using a method combining experiment measurement and numerical simulation. It is also shown by the results that if the incident angle of laser beam is in a range from 0°C to 45°C, the absorptivity increases linearly with increasing the angle, whatever the surface of specimen is in a state of solid or liquid. The data processing procedure was also improved. The complex curvilinear equation was replaced by a linear equation and the experimental data were dealt with using linear regression method.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2003年第5期449-453,共5页
Chinese Journal of Lasers
基金
国家自然科学基金 (编号 :5 98710 3 8)
西安交通大学科研基金
华中科技大学激光技术国家重点实验室资助项目
关键词
激光技术
吸收率
原位法
入射角
铝合金
Absorption
Computer simulation
In situ processing
Lasers
Linear equations
