Friction stir based additive manufacturing Process for aluminium alloy powder

Abstract

Metallic components fabricated with powder-based fusion additive manufacturing (AM) newlineprocesses are known to have defects arising from liquid-solid phase transformation. newlineEmploying friction stirring by a non-consumable rotating tool is recently proven to be a newlineviable alternative heating source, as evidenced by the powder-based Additive Friction Stir newlineDeposition (AFS-D) process principle. The process can facilitate deposition by severe plastic newlinedeformation without raising the processed powder s temperature above the melting point. newlineHowever, the added preliminary step of making compacted powder feedstock limits powderbased newlineAFS-D s productivity and poses a practical problem to its implementation. In the newlinepowder-based friction-stir additive manufacturing field, this issue is currently a significant newlinehindrance to scientific advancement, resulting in a meagre amount of research reported. To newlinemitigate the existing limitations, any attempt to develop a friction stir-based AM setup and/or newlineprocess by building deposits directly from metal powders will be beneficial to the AM newlineindustries. Therefore, the thesis aims to explore the potential use of the friction stir-based newlineadditive manufacturing process to build sound deposits directly from aluminium alloy newlinepowder. However, an attempt was first made to see the feasibility of the friction-stirring route newlineto building deposits layer-by-layer directly from aluminium alloy powder. Then, such a newlinefriction stir-based additive manufacturing setup and process were developed. Further, for newlinebetter utilization of this process in industries, the underlying process mechanics was newlineunderstood systematically. newlineThe feasibility study shows that the friction-stirring route could successfully build a layerby- newlinelayer 3D deposit directly from pure aluminium powder by feeding them ahead of a nonconsumable newlinefriction-stirring tool. In order to build deposits layer-by-layer directly from newlinealuminium alloy powder, a continuous powder feeding mechanism was integrated into a newlineconventional vertical milling machine as a part of a p