温度场分布对Ni60A熔覆层组织的影响  

Effect of Temperature Field Distribution on Microstructure of Ni60A Cladding Layer

作　　者：夏祯航 李涛[2] 詹欢 张洪潮[3] Xia Zhenhang;Li Tao;Zhan Huan;Zhang Hongchao(School of Mechanical Engineering,Dalian University of Technology,Dalian,Liaoning 116081,China;Institute of Major Equipment Design,Dalian University of Technology,Dalian,Liaoning 116081,China;Department of Industrial Engineering,Texas Tech University,TX76001,USA)

机构地区：[1]大连理工大学辽宁机械工程学院,辽宁大连116081 [2]大连理工大学重大装备设计研究所,辽宁大连116081 [3]德克萨斯理工大学工业工程系,美国德州TX76001

出　　处：《机电工程技术》2023年第1期1-4,共4页Mechanical & Electrical Engineering Technology

基　　金：国家自然科学基金资助项目(编号:5197052248)。

摘　　要：由于激光熔覆过程的工艺复杂性和材料结晶的多样性对熔覆层性能影响较大,为研究熔覆层的微观组织,从不同工艺参数出发,通过Abaqus仿真得到不同工艺参数下的温度场分布情况,然后计算出熔覆层不同深度的温度梯度、凝固速度和凝固方向,讨论了柱状晶开始转化等轴晶G/R图内的CET曲线位置及其与仿真温度场特征曲线的关系,分析了熔池凝固时定向流动对枝晶生长中断的影响。对比实验结果,较大线能量可以提高熔覆层中柱状树枝晶的比例,使组织结构紧密均匀,减少熔覆层内因硬质相分布不均导致的缺陷生成量。同时也要控制工艺参数防止其生长到熔覆层顶部。工艺参数也会影响稀释率,较大的稀释率会改变金相成分,提高熔覆层与基体性能的一致性,从而提高熔覆层断裂强度。Due to the complexity of the process of laser cladding technology and the diversity of crystalline materials influence the performance of cladding layer, to study the microstructure of cladding layer, embarking from the different process parameters, the temperature field distribution under different process parameters was obtained by Abaqus simulation, the cladding layer were calculated after the different depth of temperature gradient, solidification speed and direction of solidification. The position of CET curve in G/R diagram of columnar crystals beginning to transform equiaxed crystals and its relationship with characteristic curve of simulated temperature field were discussed. The effect of directional flow on dendrite growth interruption during molten pool solidification was analyzed. Compared with the experimental results, the higher line energy can increase the proportion of columnar dendrites in the cladding layer, make the microstructure compact and uniform, and reduce the number of defects caused by uneven distribution of hard phase in the cladding layer. At the same time, the process parameters should be controlled to prevent it from growing to the top of the cladding layer. The process parameters also affect the dilution rate. A larger dilution rate will change the metallographic composition, improve the consistency between the cladding layer and the matrix, and improve the fracture strength of the cladding layer.

关 键 词：激光熔覆 熔覆层组织 裂纹 NI60A 

分 类 号：TG665[金属学及工艺—金属切削加工及机床]