Crystal plasticity modeling of non-Schmid yield behavior: from Ni3Al single crystals to Ni-based superalloys

A crystal plasticity finite element (CPFE) framework is proposed for modeling the non-Schmid yield behavior of L1(2) type Ni3Al crystals and Ni-based superalloys. This framework relies on the estimation of the non-Schmid model parameters directly from the orientation- and temperature-dependent experimental yield stress data. The inelastic deformation model for Ni3Al crystals is extended to the precipitate (gamma') phase of Ni-based superalloys in a homogenized dislocation density based crystal plasticity framework. The framework is used to simulate the orientation- and temperature-dependent yield of Ni3Al crystals and single crystal Ni-based superalloy, CMSX-4, in the temperature range 260-1304 K. Model predictions of the yield stress are in general agreement with experiments. Model predictions are also made regarding the tension-compression asymmetry and the dominant slip mechanism at yield over the standard stereographic triangle at various temperatures for both these materials. These predictions provide valuable insights regarding the underlying (orientation- and temperature-dependent) slip mechanisms at yield. In this regard, the non-Schmid model may also serve as a standalone analytical model for predicting the yield stress, the tension-compression asymmetry and the underlying slip mechanismat yield as a function of orientation and temperature.

Automated summary

A crystal plasticity finite element (CPFE) framework is proposed for modeling the non-Schmid yield behavior of L1(2) type Ni3Al crystals and Ni-based superalloys, with parameters estimated directly from experimental data. The model accurately predicts yield stress and provides insights into tension-compression asymmetry and dominant slip mechanisms for these materials at different temperatures.