Effect of HIP'ping on deformation anisotropy in a single-crystal Ni-based superalloy

The effect of HIP'ping on plastic anisotropy of a Ni-based superalloy was studied. The orientation dependence of tensile properties was evaluated experimentally at room temperature at a nominal strain rate of 10(-3) s(-1). The results indicate that HIP'ping eliminates the non-Schmid effect by increasing the strength of the < 111 > loaded samples. This phenomenon is attributed to the influence of stress fields of pores and eutectic pools on the yielding behavior of the < 111 > loaded samples, whose deformation is confined to the gamma-channels. When deformation takes place by the shearing of gamma'-particles, the softening effect dominates and the presence of discontinuities has less or no effect on the deformation path. A new plastic anisotropy was discovered in this work. It is shown that the tensile properties along the primary dendrite growth ([001] orientation) is significantly different than along the secondary dendrite growth direction ([100] orientation). (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.