侧向送粉激光沉积中粉末与激光相互作用数学模型

Mathematical Model of Interaction between Laser Beam and Metal Powder in Laser Deposition by Side-Injection

为了确定侧向送粉激光沉积粉末到达基板时的温度状态,并分析各工艺参数对最终温度的影响,建立了侧向送粉激光沉积中粉末颗粒与激光相互作用的数学模型。结果表明:运动模型可以确定颗粒与激光相互作用时间,温升模型可以确定颗粒温升与作用时间的关系;运动模型中,喷嘴倾角为临界角时时间最长,激光光斑半径越大时间越长;温升模型中,粉末直径越大温度升高越慢,激光功率越大温度升高越快,光斑半径越小,温度升高越快;两个模型结合即可计算特定工艺条件粉末到达基板时的状态。

In order to determine the temperature state of the laser deposition powder on the substrate, and analyze the influence of the process parameters on the final temperature, a mathematical model of the interaction between the powder particles and the laser was established. The simulation results show that the motion model can determine the time of the interactions between the particles and laser,and the temperature rise model can determine the relationship between particle temperature rise and time. In motion model, the time is longest when nozzle angle is as critical angle, the bigger the laser spot radius is, the longer the time is. In temperature rise model, the bigger the particle diameter is, the slower the temperature rise s, the more the laser power is, the quicker the temperature rises, the smaller the spot radius is, the quicker the temperature rises.Combining two model can calculate the state of powder reaching the substrate finally in specific conditions.