Tensile Testing on Formability of Different Gauge Tailor-Welded Blanks

Abstract

The formability of tailor welded blanks (TWBs) which combined with different blanks is difference to single material blanks. It has the benefits to improve the forming process by the study on the formability of TWBs. As an effective and practical material property test method, tensile test were applied to study it. Base material and tailor welded blanks test specimens had been designed for tensile testing and the test was carried out. The strength and plastic properties of different TWBs were acquired and the results were discussed. The results of tensile test indicated that the tensile strength of TWBs was between higher strength base material and lower one but formability was lower than any base material. At the same time the weld line location in the TWBs had a significant impact on the formability also. Tailor welded blanks (TWBs) are composed of more than two materials with similar or different strengths or thicknesses joined together to form a single part before the forming operation (1). In recent years, different gauge TWBs are commonly used in automotive panels manufacturing to satisfy the demand of the automotive industry's developing new cost effective methods to enhance the performance of the vehicle weight reduction and fuel economy (2). While the character and behavior during the forming process of different gauge TWBs is not alike single thickness (material) sheet behavior. The forming behavior of TWBs is critically influenced by thickness and material combinations of the blanks welded and weld line location etc. Considerable investigations on the behavior of different gauge TWBs have been done in the aspect of stress-strain curve, forming limit strain, dome heigh, deep-draw ability, and weld line movement based on experimental and computer simulation method (3-7). However, little has been reported on formability investigation of different gauge TWBs by tensile testing (8, 9).