铸铁表面激光熔凝行为及温度场数值模拟

为明确铸铁表面激光熔凝过程的热响应规律,考虑随温度变化的材料热物性参数和相变潜热影响,建立铸铁表面激光动态熔凝的三维数值模型并进行了验证,预测值与试验值吻合良好,采用该模型分析了热响应温度场规律及不同工艺参数的映射关系.结果表明,铸铁表面激光熔凝较钢材可获得更大的熔透深度,熔池内、外形成较大温度梯度且分别以深、宽方向分...

Numerical simulation of dynamic laser melting behavior and temperature field on cast iron surface

For explicitly understanding the thermo-mechanism of laser melting process on cast iron, a validated dynamic three-dimensional numerical modal for this process was established by taking into account the thermal physical parameters and latent heat of the material. The temperature field and the relationships between different process parameters were studied with this model, and the simulation results were in accordance with the experimental results. The results indicate that the penetration depth of the laser melting process on cast iron is grater than that on the steel. The large temperature gradients inside and outside the molten pool are dominated by the depth and width components respectively. A larger temperature gradient is gained through reducing scan speed and spot size. The pool is shrunk by the increase of scan speed and spot radius; the solidification speed is raised with the increase of laser scan speed and reduction of the spot size.