送粉式平面激光熔覆搭接模型构建及实验分析

Construction and Experimental Analysis of Planar Laser Cladding Lap Model by Powder Feeding

为解决编程繁琐性,实现编程的自适应性,得到较为理想的平面熔覆质量,建立了送粉式平面激光熔覆搭接模型,由单道熔覆线熔宽W=1.95 mm,熔高H=0.64 mm,计算得到了搭接轨迹中心距C=1.42 mm,通过Simplify3D软件生成填充挤出线宽度k=100%与80%两种NC轨迹代码。采用侧向送粉方式,进行316L金属粉末激光熔覆试验,分析了熔覆层搭接形貌、微观组织及沿熔深方向上的显微硬度变化规律。试验表明:填充挤出线宽度k=80%相比k=100%时平整度有所改善,表现在凹坑的深度明显变浅、敞口宽度变窄;熔覆层与基体为冶金结合,无气孔产生,熔覆层组织表现为枝晶、等轴细晶、平面晶;熔覆层顶部到基体显微硬度大致呈现先增大后降低至基本趋于平稳的趋势,其中最大硬度值为423.4 HV,测量得到熔覆层组织硬度大约是基体的1.5~2.4倍。

In order to realize the adaptability of programming and obtain the ideal quality of planar cladding, a planar cladding lap model based on Simplify3 D slice was established in this paper. The weld width W=1.95 mm and weld height H=0.64 mm was measured from the single cladding line, the center distance of the lap trajectory C=1.42 mm was calculated. The NC path codes of filling extrusion line width k=100% and 80% generates was obtained from the software. The laser cladding experiment of 316 L metal powder was carried out by lateral powder feeding, the morphology, microstructure and microhardness of the cladding layer in the direction of deep penetration were analyzed. Results show that the k=80% the width of the filled extrusion line is better than the k=100%, the cladding layer of the k=80% shows that the depth of the groove is obviously shallow and the opening width is narrow. Dendrite、equiaxed fine crystal and planar crystal the structure of the cladding layer is observed. The microhardness increases first and then decreases to the basic level is measured from the top of the cladding layer to the matrix. The maximum hardness value is measured about 423.4 HV. The microhardness of the cladding layer is about 1.5~2.4 times that of the matrix.