Hot compression deformation behavior and processing map of pure nickel N6

Hot compression deformation experiment of pure nickel N6 was conducted on a Gleeble-3800 thermomechanical simulator at a deformation temperature range of 800 to 1100℃, a deformation rate range of 5 to 40 s^-1 and at a deformation of 70%. The hot deformation behavior of this material was analyzed at high temperature and high deformation rate. The microstructural evolution and the flow stress curves were obtained at different deformation parameters. The processing maps were drawn by using the dynamic material model. Through analyzing the microstructures and the processing maps, two reasonable regions are introduced for processing pure nickel N6:the deformation temperature range of 1000 to 1100℃ and the deformation rate range of 5 to 7 s^-1 or 20 to 40 s^-1; the deformation temperature range of 800 to 900℃ and the deformation rate range of 5 to 10 s^-1. In these two regions, the microstructure of pure nickel N6 is uniform, while in the region of rheological instability the microstructure is disordered and the grain size is varied. The grain size of pure nickel N6 after hot deformation goes up as the deformation temperature rises or the deformation rate declines.