EFFECT OF PROCESS PARAMETERS ON TIG ARC WELDING OF AI-6063 SiCP METAL MATRIX COMPOSITES

Abstract

In the present work TIG are welding behaviour of a SiC particulate reinforced Al-alloy 6063 composite sheets of size 6mm using TIG welding technique ,under high energy fusion conditions Al MMC was casted by 7% SiCp using stir casting technique The different reaction mechanisms between SiC particulates , both the molten aluminium and their alloying elements (Mg,Fe,Si) are discussed The high aspect ratio of the reinforcement is the main microstructural factor ,which controls the weldability of this kind of composites .Due to the higher welding input energy leads to the formation of aluminium carbide (A14C3 ), has got a needle like structure which increased the brittleness of MMC . TIG welding has been done by a groove angle of 900 using the filler wire ER4043 The mechanical properties of the TIG welding were compared with base material and the results were co related with microstructural modifications . Welded specimens exhibited a high joint efficiency as compared to the base material. TIG welding lead to the aggregation of the particles and lead to non uniformity of hardness in the welded area was explained by different microstructural homogeneity in the transition from base to weld zone.