Plastic deformation behavior and processing maps of a Ni-based superalloy

Hot compression tests of a kind of Ni-based superalloy were performed under the conditions of temperatures of 1223 K, 1273 K, 1323 K, 1373 K, 1423 K, the strain rates of 0.001 s(-1), 0.1 s(-1) 1, 1 s(-1), 3 s(-1), 30 s(-1). Processing maps were established on the basis of the data achieved from the hot compression tests by using the principle of dynamic materials modeling. The microstructure evolution and the dislocation of the samples after tests were observed. Through the analysis of the processing maps, it can be known that the samples in the process of the deformation can achieve the peak efficiency of about 35% when the temperature is above 1273 K, strain rate locates in 0.1-2 s(-1). The result of metallographic analysis shows that the proportion of dynamic recrystallization in the peak efficiency domain is higher than that in other domains. It can be found that the dislocation density is very high in the low efficiency or instability domain where dynamic recrystallization does not occur or the proportion of dynamic recrystallization is low. The optimum deformation condition of the Ni-based superalloy can also be found through the analysis of processing maps. (C) 2014 Elsevier Ltd. All rights reserved.