EVOLUTION OF THE STRUCTURE OF A 60/40 BIPHASED BRASS DURING HIGH TEMPERATURE TENSILE TESTS.

High temperature tensile tests have been made on a biphased alpha - beta brass at initial strain rates varying between 6. 9 multiplied by 10** minus **5 and 6. 9 multiplied by 10** minus **2s** minus **1. The variations of the yield stress, the strain rate sensitivity parameters m, and the morphology of the rupture (presence or absence of necking) with the strain rate reveal the existence of two ranges of deformation processes. Optical microscopic examinations and X-ray diffraction patterns prove that dynamic recrystallization of the alpha phase occurs for some experimental conditions; the degree of dynamic recrystallization being favored by decreasing deformation rate and increasing strain. Moreover, microscopic examinations show that at low deformation rates the following microstructural changes appear during straining: a coarsening of the alpha and beta grains, a decreasing of the beta percentage and an anisotropy of the alpha grains.