EFFECT OF DIFFERENT TOOL PIN PROFILE ON THE MECHANICAL PROPERTIES OF MAGNESIUM BASED ALLOY AZ91 BY FRICTION STIR WELDING

The usage of magnesium in automotive applications is also assessed for the impac t on environmental conservation. Recent developments in coating and alloying of Mg improved the creep and corrosion resistance properties of magnesium alloys for elevated temperature and corrosive environments. The results of the study conclude that reason able prices and improved properties of Mg and its alloys will lead to massive use of magnesium. Compared to using alternative materials, using Mg alloys results in a 22% to 70% weight reduction. The joining of magnesium alloy was successfully carried out u sing FSW technique. . In this paper effect of different tool pin profile on mg az 91 alloy is calculated by using FSW Welding. The samples were characterized by mechanical properties like tensile strength, impact strength, Vicker hardness and mic rostructure . The nominal chemical composition of AZ - 91 magnesium alloy is 9% Aluminium (Al) and 1 % Zinc (Zn) and balance Mg. The FSW was carried out using CNC vertical milling machine . The optimum results by taguchi L9 method are carried out at a rotation al speed of 500 RPM and feed is 50 mm/min with a cylindrical threaded tool was best to maximize the tensile strength and Observed that the 600 rpm, 70 mm/ min feed and cylindrical threaded was best to maximize the impact strength. The best to minimize th e vicker hardness at rotational speed the 600 rpm and 60 mm/ min feed and taper threaded. Fine structure in the weld may be divided into three regions: fine re - crystallized grains around the weld center, the grains in the base metal highly elongated and pancake shaped and grain having great deformation in TMAZ. Compared with the BM, very fine grains were present in the SZ, due to dynamic recrystalization