DIFFUSION BONDING OF SUPERPLASTIC AI ALLOY LC4

Diffusion bonding of supcrplastic Al alloy LC4,with prior surface treatment of organicsolution protecting coating after electroplishing and stainless steel wool brushing,wasperformed by Gleeble test machine under conditions ranged 490—530 ℃,1.0—3.0 MPa.30—180 min and vacuum of 1.0×10~(-3) Pa.The joints were examined to have similarstrength and microstructure to the base metal Discussion was made on the effect ofsuperplastic treatment on bonding.The micromechanism for diffusion bonding of super-plastic metal was suggested as the migration of original bond interfaces caused by atomicdiffusion and grain growth. Experimental results for the alloy as quench-aged state werepresented to compare with the superplastic one.