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为了降低激光熔覆过程中熔覆层热应力从而减少裂纹的生成,提出了一种通过改变激光功率密度分布来控制熔覆层裂纹的方法,并用数值模拟的方法对均布及凸字形光斑熔覆过程进行了热力耦合有限元分析。结果表明,用均布光斑熔覆呈现出激光加工典型的快速加热、快速冷却特征,而采用凸字形光斑可在一定程度上起到预热、缓冷的效果,从而降低了熔覆区与非熔覆区的温度梯度,另外,在熔覆效果相当的前提下,其熔覆层热应力也较小,因而可以有效地减小熔覆层的开裂趋势。
In order to reduce the thermal stress of the cladding layer during laser cladding and reduce the generation of cracks, a method of controlling the cladding layer crack by changing the laser power density distribution is proposed. By using the numerical simulation method, The process of thermal coupling finite element analysis. The results show that the uniform laser spot welding process shows a typical rapid heating, rapid cooling characteristics, and the use of convex spot to a certain extent, preheat, slow cooling effect, thereby reducing the cladding area and non In addition, under the premise of equivalent cladding effect, the thermal stress of the cladding layer is also small, so the cracking tendency of the cladding layer can be effectively reduced.