Residual Stress and Texture Analysis of Leaf Spring Failure

Abstract

The leaf spring fabrication process, which consists of various processes, will result in susceptibility to atomic defects. Therefore, the identification of defects at the atomic scale through crystallography is very important in analyzing the slip mechanism to minimize the occurrence of leaf spring failure. This study aimed to analyze the causes of leaf spring failure by crystallography through an experimental approach. Residual stress testing was carried out using XRD with the sin 2 approach. The Sin 2 method uses angles -20°, -16°, -12°, -4°, 0°, 4°, 12°, 16°, 20°. Crystal orientation and texture were performed using MAUD 2.94 software to analyze the Miller index and crystallographic orientation distribution. Hardness test using Vickers micro with indentation points near and far from the leaf spring fracture surface. Leaf spring fracture morphology was tested using a DSLR camera and Scanning Electron Microscopy (SEM). The results of the residual stress analysis show a wavy elliptical curve indicating that the broken leaf spring has a shear stress and a stress gradient. The resulting residual stress has compressive properties with a value of -278.5±17.4 with the resulting crystal orientation consisting of miller index planes (110), (200), (211). The crystal orientation plane (200) has a characteristic texture that is oriented towards the Normal Direction (ND). Normal direction is indicated by a high probability value of 1.20. A high probability indicates that the leaf spring has material surface defects. The void is the beginning of the formation of crack initiation and becomes the center of stress concentration.

Keywords

• failure
• leaf spring
• residual stress
• texture