The Optimization Of Welding Groove Form For Aluminum Alloy Laser-arc Welding

In order to solve the problem of aluminum plate by arc welding such as: large weldingdeformation,little depth-to-width ratio and lower production efficiency.We may use laser arc hybrid welding technology that has advantages such as the small welding deformation,higherdepth-to-width ratio,higher welding speed and so on.Combined with laser-the advantages of compound welding arc,To carry out the laser-arc hybridwelding method with the medium thickness Aluminum Alloyplate heat exchanger which has a small weldingdeformation and high intensity by one-time welding.Using YAG laser-MIG arc hybrid welding to take bead on plate and butt weldingresearch on 10 mm thick aluminum plate.It mainly studied the influences of arc energy on the weld penetration,weld width,weld porosity rate,droplet transfer and so on for getting the best welding parameters.Besides,it carried the orthogonal nondestructive tests on the unilateral groove angle of 20 degrees,30 degrees,40 degrees and blunt edge height of 3 mm,4 mm,5 mm Y groove specimen.Observe and analyzethe Aluminum Alloy weld specimens' blowhole rate,macro morphology and microstructureby X ray microscope and metallographic microscope;Test and analyze the Aluminum Alloywelding jointstensile strength,the impact toughness,bending properties and hardness by micro-hardness instruments,tensile,bending and impact testing machine to get the best welding groove form.The results show that in the aluminum alloy plate welding get the biggest welded joint of the width and depth of molten while minimal porosity is lower.When the welding current is 220 A,and the arc voltage is 21.2V,defocusing amount is-2mm,laser power is 3kw,the welding speed is 1m/min,heat source position 3mm and protection gas flow welding torch to 20L/min.In addition,also found that with the increase of arc energy,a single droplet transition time are all showed a trend of decline.In the butt welding,when the groove angle of 20° and blunt side of 3 mm,impact toughness of weld center and bending is the optimal performance.When the groove Angle of 20°,blunt edge respectively is 4 mm and 5 mm,joint tensile strength and impact toughness,in turn,the optimal fusion line.With minimal joint porosity and back bending performance of the optimal respectively in the blunt edge is 4 mm,groove Angle of 30° and 40° respectively.Results shows that,the size of the groove on the micro hardness and microstructure of joint has no obvious influence.