采用FLUENT软件建立钛合金激光熔覆熔池的数学模型, 对高强度激光辐射下熔池的产生和发展进行数值模拟, 分析了激光辐照时间对熔池表面温度场、流场速度分布的影响, 对模拟结果和实际熔池的宽度与深度进行比较。结果显示, 激光熔池在0.1 s之内, 熔池温度、流动速度和几何尺寸急速增大, 0.2 s之后, 熔池的最大温度和最大速度趋于稳定, 激光能量源呈高斯模式下激光熔池表面中心温度最高, 近边缘处的流体速度最大。由于熔池自由表面的波动和外溢飞溅等现象, 模拟熔池宽度明显大于实际熔道。

The mathematical model of laser cladding pool on titanium alloy surface was established using fluent software. The generation and development of molten pool under high intensity laser radiation are numerically simulated. The influence of laser irradiation time on the temperature field and flow field velocity distribution on the molten pool is analyzed. The width and depth of simulated molten pool and actual laser cladding channel was compared. The results showed that the temperature, flow velocity and geometric size of the molten pool developed rapidly within 0.1 second. And then the maximum temperature and maximum velocity of the molten pool tended to be stable after 0.2 second. The highest temperature is the surface center of the laser molten pool and the maximum fluid velocity is the surface edge. It is agree with the gaussian mode of laser energy source. Due to the heat loss and mass loss of the fluctuation and the splashing of the free molten pool, the width of the simulated molten pool is significantly larger than that of the actual melting channel.