Effect of Thickness and Grain Size on Flow Stress of Very Thin Brass Sheets

Abstract

The deformation behavior of metal sheets is strongly influenced by the extent of miniaturization due to the size effects (specimen size and grain size). In this paper, the effect of thickness and grain size on the flow stress of very thin brass sheets has been investigated by conducting microstructural studies and uni axial tensile tests on annealed specimens of thickness in the range 50 μm-200 μm.To obtain a large variation in thickness to grain size (t/d) ratio, different combinations of annealing temperature and time have been chosen. The effect of t/d ratio on yield stress and flow stress has been analysed using the tensile test data. For larger values of t/d ratio (6 -18), yield strength and flow stress at different strain levels increased with increase in t/d ratio. But flow stress decreases with increasing t/d when the values of t/d ratio are less than 3 due to the size effects.