Effect of Micro-Sized on Thin plate Specimen using Fractographic Analysis

Abstract

In the last four decades, the car body thickness has reduced significantly from almost 1.5 mm tobelow 0.5 mm. This was mainly due to the demand for weight reduction for saving more fuel cost.Besides being thinner, maintaining the high strength of car body was possible by using a newlydeveloped high-strength steel thin plate. However, mechanical properties of bulk materials whichusually tested using a standard big size sample are not necessarily representing the actual propertiesof the material when dealing with very thin and small size components. This drives the research onthe mechanical properties of the micro-sized specimen for the production of tiny metal-basedcomponents. In this study, tensile and fracture behaviors of the micro-sized specimen wereinvestigated. The materials used were 100 and 300 micron stainless steel S304 thin plates, the testswere carried out on specimens of ASTM A313M spring steel materials. The results showed that100 micron thin plate exhibited higher tensile strength with no clear evidence of yielding ascompared to 300 micron plates. The fracture morphology images observed by Scanning ElectronMicroscopy (SEM) revealed that both specimens fractured in ductile mode. Formation of dimpleson the fracture surface could be recognized easily in 300 micron sample at higher magnification ascompared to 100 micron sample