微束等离子粉末熔覆金属零件直接快速成形研究

Direct Rapid Forming Study of Metal Parts Based on Micro-plasma Arc Cladding

对微束等离子熔覆金属零件直接快速成形技术进行了初步研究。构建了该成形系统的软、硬件实施。利用该系统制造了一个由80层熔覆层堆积而成的简单空心筒状零件,其直径误差小于5%,高度和垂直度误差小于2%。对成形件的组织分析表明,成形件中部典型组织表现为短小枝晶,层与层结合处可看到明显的组织分界,结合处组织向等轴晶转变。熔覆率为132 g/h,粉末利用率为85%～90%。硬度测试表明,成形件硬度主要分布在200～260 HV,上部和底部硬度值略高于中部,硬度值为260～320 HV。

This paper presents an preliminary investigation on a novel rapid prototyping technique based on micro-plasma arc cladding that is utilized to direct rapid fabricate metal parts. The implementation of hardware and software was established. A hollow cylindrical part with 80 layers was built, its deviation of verticality is less than 5 %, height and diameter are less than 2 % Metallography examinations of the part show that in the middle of the part mostly display shortness dendritic crystal structure, clear boundary is found between the bond zone of one layer and the following layer, and the structure of boundary exhibits equiaxed grains. Deposition efficiency was 132 g/h, and the powder utilization ratio reached 85 % - 90 %. The hardness test shows that the hardness distribution of the part is mainly in 200-260 HV, and the hardness value of upper and bottom is 260-320 HV, higher a little than that of middle.