摘要
为解决金属材料在激光辐照过程中因时变能量沉积所致的热响应问题,构建了由多层氧化膜生长模型、吸收基底表面多层吸收膜模型和热传导方程组成的能量沉积-热响应时变耦合模型。多层氧化膜包括Fe2O3、Fe3O4和FeO等三层,Fe2O3和Fe3O4氧化膜初期以线性规律生长,后期以抛物线规律生长,其中Fe3O4氧化膜在250℃以上开始生长;FeO氧化膜在570℃后以抛物线规律生长。利用吸收基底表面多层吸收膜模型计算了不同厚度多层氧化膜的反射率;利用热传导方程计算样品温度,联立求解了激光辐照过程中样品温度和反射率的变化历程。最后,建立了积分球反射率测量装置,在线测量了不同功率1.06μm连续激光辐照过程中45#钢的反射率和温度,实验结果与数值模拟结果吻合较好。
To describe an effective heat source caused by the reflectance variation under laser irradiation,a dynamic model of reflectance evolution consisting of a multi-layer oxide film growth model,a multi absorbing film on absorbing substrate model and a heat diffusion model is build.The oxide film consists of three layers of Fe2O3,Fe3O4 and FeO.The oxidation rates of Fe2O3 and Fe3O4 layers are represented by a linear rate law at initial stages and a parabolic rate law at later stages than 100 nm.The Fe3O4 layer and FeO layer form films from 250 ℃ and 570 ℃.The multiabsorbing film on absorbing substrate mode is used to calculate the reflectance of the multi-laryer oxide film and its temperature is computed by the thermal conductive equation,by which the time dependance of reflectance on temperature is obtained.Finally,a time dependence of reflectance and temperature are calculated.The total integrated scattering measurement device is established to measure the reflectance and temperature of the 45 # steel irradiated by 1.06μm cw laser with different powers in-situ.The numerical solutions are in agreement with the experimental data.
出处
《光学精密工程》
EI
CAS
CSCD
北大核心
2014年第8期2061-2066,共6页
Optics and Precision Engineering
基金
激光与物质相互作用国家重点实验室基金资助项目(No.SKLLIM1301)
