Mechanical Properties and Microstructures on Dissimilar Metal Joints of Stainless Steel 301 and Aluminum Alloy 1100 by Micro-Resistance Spot Welding

Aluminum and stainless steel are metals that have some mechanical property advantages. Welding technology has been developed to join both different and dissimilar metals applied in a construction. The property advantages have been used to improve the performance of a construction. However, welding performance still creates a problem as a result of properties’ differences in metals. This study investigated the mechanical properties of a steel-aluminum joint with the thickness of less than 1 mm, welded by resistance spot welding (RSW); it is called a micro-RSW. Mechanical properties of the joint were analyzed by tensile test and were measured at the fracture area on the tensile test specimen. Moreover, it also analyzed intermetallic microstructure in the nugget or welding joint. Welding time of 8 CT was an optimum parameter on a welding process to get the maximum load. The fractographic structure of a stainless steel-aluminum joint showed a brittle nugget. Moreover, the fracture area on the aluminum side was larger than that of the stainless steel. Intermetallic compound (IMC) was created by melting and joining it through the heat input in the welding process. IMC in SS301-AA1100 nugget affected a brittle joint.