Experimental and Finite Element Investigation of Resistance Spot Welding of Aluminum AA 2017

Abstract

Resistance spot welding is a process in which contacting metal surfaces are joined by the pressure and heat obtained from resistance to electric current flow. It is widely accepted in the industry due to its advantages in high speed and suitability for automation. The target is to investigate mechanical properties of RSW, optimize, enhance strength of fabricated by RSW of aluminum, by optimizing welding parameters like time, shape of electrodes and sheet thickness of the spot welded joints finally the checking the micro hardness of the weld structure. In addition, the RSW process is a complicated process that includes electrical, thermal and mechanical phenomena. Percentage contributions of the thickness of aluminum, thickness of cover sheet, and a welding time are 3.89%, 3.25%, and 84.39% respectively. It is found that the degree of importance of process parameters in attaining the tensile strength of weld joint greatly depends on the welding time. In the case of deformation, the percentage of contributions of the thickness of aluminum, thickness of cover sheet, and welding time is 1.17%, 8.73%, and 80.88% respectively. A welding time have the most significant factor. In the case of temperature, the percentage of contributions of the thickness of aluminum, thickness of cover sheet, and welding time is 9.96%, 87.82%, and 1.66% respectively. A thickness of cover mild steel sheet has the most significant factor. Validated result of two selected most significant factors (weld temperature and weld time) validation shows for FEA and Experimental works shows good agreement at weld temperature response, with maximum error of 10.62% that due to nature of the material and influence of other welding parameters such as welding current, thickness of weld cover and welding voltage and thickness of weld itself., as shown the micro hardness test result for the given test specimens HAZ and NZ is various from one region to another. But still it needs further works by changing some weld parameters of the study to know what will happen around the weld zone of RSW