TIG WELDING OF PARTICLE REINFORCED • A1-A1203. COMPOSITE

Abstract

Tungsten Inert Gas (TIG) welding of particle reinforced composites containing fine particles has been investigated in respect of joint design, and welding current. The composites have been synthesized in the laboratory here by stircasting technique and the plates from ingots have been used for joining in a butt joint or V-groove joint with or. without filler. In absence of fillers, the particles from composites ejected out of the weld pool towards the nozzle. Presence of particles in the weld head conirihuies to a good strength and a welding current of 150 A to 180 A results in a satisfactory joint. The use of low current of 120 A may cause incomplete fusion of the root of grooved weld joint. Square butt welding of 8 mm. thick plates of composites is difficult to carry out due to high cracking susceptibility of joint from lack of penetration. During welding the welding arc was found to be disturbed by the presence of porosity and particles in the base material. These behaviour has been found to badly affected the weld quality. During welding some oxide particles are also found to be deposited at the torch causing difficulties in welding