Effects of processing parameters on liquation cracking of 6005A alloy weldments

The effects of the characteristic microstructure developed in extruded 6005A alloys on tensile properties, fatigue strength, and liquation cracking in the heat affected zone of weldments were investigated, An insitu observation of the grain growth occurring in the sample was made with an optical microscope with a hot stage to determine the temperature of the excessive grain growth during extrusion. The extruded samples were heat heated under various conditions and welded using a gas metal arc welding process. The results indicated that liquation occurred mainly at coarse grain boundaries and significantly influencing the mechanical properties of the joint.