TIG용접 적용 금속AM에서 이방성 개선에 관한 연구

Abstract

With the appearance of Additive Manufacturing (AM), manufacturers are able to produce goods in various shapes. In the field of metal processing, AM is divided into powder method and wire method. At the initial stage of AM, study on powder based AM was actively conducted because of its high precision but, at present, its application is limited to the mock-up of new products or the sample experiment due to the high cost of powder material and the complex device structure used in the powder method. On the other hand, wire-feed AM of metal is widely used for manufacturing metal products in aerospace and aviation industry and other various fields contributed by its high rate of deposition. But, in the event wire-feed AM is layered or deposed, it gives a rise to epitaxial grain growth in the layered or deposition direction, which causes the formation of strong columnar structure that leads to anisotropy in mechanical property. This anisotropy is observed in various forms depending on patterns of columnar structure and deteriorates the product quality. Accordingly, there is an arising necessity to develop the method of improving anisotropy in mechanical property caused by wire-feed AM of metal in order to address above mentioned issues. This study has defined additive mechanism from the perspective of AM of metal, made an observation of the mechanical property and micro-structure from deposition of stainless steel and Ti-6Al-4V by varying their deposition paths, and, through interpass peening, improved anisotropy in mechanical property caused by deposition.