基于等离子熔覆快速成形零件的组织与性能

Study on structures and properties of part made by micro-plasma arc direct metal formation

为了采用微束等离子弧粉末熔覆快速成形技术,在低碳钢基板上进行了铁基合金粉末Fe313的直接金属成形试验.通过光学金相显微镜和扫描电镜观察分析了成形金属零件显微组织和形貌,并利用维氏硬度计测试了熔覆层的显微硬度.结果表明,成形件中部典型组织表现为岛状的M-A组元,层与层结合处可看到明显的组织分界,先成形层受到后成形层的热影响,会引起晶粒细化,成形件硬度沿高度呈U形分布,中间熔覆层由于后道焊缝的回火作用而有所软化,导致硬度降低.

The deposition experiments were done on the mild steel by micro-plasma arc powder overlaying rapid prototyping technique with Fe313 alloy powder.The microstructures and morphologies were observed by metallographic microscope and SEM,the microhardness was tested by vickers.It was showed that the middle layer displayed insular M-A component structure,and the interface between layers was evident.The microstructure of Fe-based deposited layer was affected by the subsequent overlaying with annealing process,and the crystalline grain refined.The hardness distribution curve of the cylindraceous part was as U shape,the middle layer was soften because the drawing effect of subsequent layers.