Effects of Rolling Reduction on Cold Forming Properties of Commercially Pure Titanium Sheet

Abstract

Different cold rolling reductions were adopted for commercially pure titanium sheet. Cold forming properties were investigated by a microstructural analysis, Vickers microhardness and erichsen value measurements. The results have shown that Cold rolling resulted in refined alpha grains. Alpha grain size was refined further by greater cold reduction. Alpha grain sizes of the specimens of processing 1, 2 and 3 reached 30.90 μm, 26.48 μm and 20.58 μm, respectively. Cold forming properties were affected by different alpha grain sizes. The hardness and erichsen value reached the lowest and the highest values for the specimens in processing 1. The hardness increased and erichsen value decreased due to the finer alpha grain size for the specimen which was cold-rolled at a reduction of 50% in processing 2. Erichsen test results of the specimens of processing 3 had the lowest values due to the deformation of a reduction of 70%. Cold forming properties of the specimens of processing 3 were deteriorated, this is because deformation leads to the high dislocation density and the stored energy increases with accumulated strain after deformation.