TC4钛合金电弧增材制造叠层组织特征

Microstructural characteristics of wire and arc additive layer manufacturing of TC4 components

采用CMT电弧增材制造技术制造了TC4钛合金薄壁墙构件,并对其组织特征进行了研究.结果表明,在电弧增材制造过程中,受其热输入、多次热循环及冷却速度的影响,在其构件中产生了从高温保留下来的贯穿数个堆积层的原始β柱状晶晶界、水平层带条纹、马氏体组织和网篮组织等.显微硬度显示,中下部区域硬度相对较高,平均硬度为336HV 0.1,上部显微硬度有明显降低,平均硬度为323.3HV 0.1.

Wire and arc additive layer manufacturing(WAALM)is a novel manufacturing technique in which metal components can be fabricated layer by layer.In this study,microstructural characteristics of TC4components after CMTWAALM deposition were investigated.During arc additive manufacturing process,epitaxial growth of prior columnarβ-grain boundaries that were from the high temperature,horizontal stripes,martensite and basket weave microstructures formed due to the heat input,multi heat cycles and cooling rates.The microhardness values at the middle and bottom regions(about336HV0.1)were higher,while those at the top regions were significantly decreased(about323.3HV0.1).