Effect of computer controlled pulsed current tig welding parameters on mechanical properties of aa6061 aluminium alloy

Abstract

Pulsed Current Tungsten Inert Gas Welding Design of Experiments newlineRegression Analysis Analysis of Variance Response Table Normal newlineProbability Plot Tensile Properties Metallurgical Properties newlineThe use of nonheat treatable fillers which can resist hot cracking is more meaningful newlinein welding 6xxx series AlMgSi alloys In these alloys as long as the weld metal newlinecontains 3Percent Mg or more hot cracking is not a serious problem Post weld solution newlinetreatment is often not necessary in 6xxx series alloys and thus a direct aging treatment newlinecan be employed Another way of controlling solidification cracking is to refine the newlinefusion zone grain structure Coarse columnar grains are often more susceptible to newlinesolidification cracking than fine equiaxed grains This may be because fine equiaxed newlinegrains can deform to accommodate contraction strains more easily newlineTwo relatively new techniques current pulsing and magnetic arc oscillation have newlinegained popularity because of their striking promise and the relative ease with which newlinethese techniques can be applied to actual industrial situations with only minor newlinemodifications to the existing welding equipment Current pulsing has been used by newlineseveral investigators to obtain grain refinement in weld fusion zones and newlineimprovement in weld mechanical properties Significant refinement of the newlinesolidification structure has been reported in aluminium alloys austenitic stainless newlinesteels nickel base alloys high strength steels titanium alloys newlineIn most of the weldments of AlMgSi alloy the fracture has been found to take newlineplace in the weld region under static and dynamic loading However the use of newlinepulsed current TIG welding has been found to improve the tensile and impact newlineproperties of the weldments compared to those of continuous current TIG welds of newlinethis alloy By keeping all the above aspects in mind the present investigation has been newlinecarried out to attain the following objectives i Developing mathematical models to newlineevaluate the mechanical yield strength tensile strength elongation impact toughness newlineand hardness propertie