摘要
建立了激光熔凝镁合金有限元模型,模型中考虑了镁合金热物性参数的非线性、相变潜热和熔化潜热,分析了激光熔凝镁合金温度和熔池形态的变化规律。结果表明:由于激光熔凝过程前面对后面的预热作用等,激光熔凝镁合金的等温线呈非对称性分布,且伴随激光熔凝过程的进行,熔池的纵截面形貌由月牙形变化到半泪滴形;由于镁合金试样长度、宽度方向总的传热热阻的差异,激光熔凝镁合金正面形貌为椭圆形;因为熔池前端和熔池后端接触试样的温度差异,熔池前段比熔池后端等温线密集;由于熔池边缘通过热扩散消耗的能量大等的影响,当激光的功率不能保证辐照区域都熔化的条件下,伴随激光光斑半径的增加,激光熔凝镁合金的正面熔池面积减小。
The finite element model of laser fused magnesium alloy was established.The nonlinearity of thermophysical,latent heat of phase change and latent heat of fusion of magnesium alloy were considered.The variation of temperature and molten pool morphology of laser fused magnesium alloy were analyzed.The results show that,the isotherm of the laser fused magnesium alloy is asymmetrically distributed due to the preheating effect of the laser fusion process.With the progress of laser melting process,the longitudinal section morphology of molten pool changes from crescent shape to half teardrop shape.The difference of total heat transfer and thermal resistance in width direction due to the length and with of magnesium alloy samples,the front morphology of laser melting magnesium alloy is elliptical.Because of the temperature difference between the front end of the molten pool and the back end of the molten pool,the isotherm of the front section of the molten pool is denser than that of the back end of the molten pool.Due to the influence of the energy consumed by thermal diffusion at the edge of the molten pool,when the power of the laser can not guarantee the melting of the irradiated region,with the increase of the radius of the laser spot,the area of the front molten pool of the laser melting magnesium alloy decreases.
作者
庞铭
浮艺旋
PANG Ming;FU Yixuan(Airport College,Civil Aviation University of China,Tianjin 300300,China)
出处
《热加工工艺》
北大核心
2019年第20期110-113,共4页
Hot Working Technology
基金
国家自然科学基金项目(U1633111、51206179)
中央高校基本科研业务费专项资助项目(3122018D020)
中国民航大学蓝天青年科研资金资助项目(20180322.3)
关键词
激光熔凝
镁合金
非对称性
熔池
laser melting
magnesium alloy
asymmetry
molten pool
