Mechanism of improved intermediate temperature plasticity of nickel-base single crystal superalloy with hot isostatic pressing

Abstract

In this work, we investigate the effect of hot isostatic pressing on the intermediate temperature tensile property of nickel-base single crystal superalloy. The experimental results indicate that the hot isostatic pressing improves the intermediate temperature plasticity of single crystal superalloy from 6.4% to 9.3%, but the yield strength remains unchanged. In addition, the fracture surface is changed by hot isostatic pressing, the microporosities disappear in the fracture surface under hot isostatic pressing, and an initial crack is formed from the region of plenty of stacked slip planar instead of microcracks by microporosities. The mechanism of the improvement of plasticity and the change of fracture behavior is explored in detail. The application of hot isostatic pressing reduces the size and volume faction of microporosities, which makes it difficult for the crack initiation and propagation, and further leads to the improvement of plasticity.

Keywords

• Single crystal superalloy
• Hot isostatic pressing
• Plasticity
• Microporosity
• Mechanical properties