Preparation of the close cross-section component of NiAl-based alloy by a novel combined sintering method

Abstract

In this study, to overcome the bottleneck of forming NiAl for aerospace applications, a novel combined sintering method based on hot-press sintering, which divides the components into various parts and compacts them gradually, is proposed and studied. Two typical close cross-sectional components (tube-like components and conical tube components with flanges), which are highly demanding and more challenging to obtain for NiAl intermetallic, were prepared and analyzed in detail. Based on these results, both prepared components were fully dense. In addition, as shown by the bending tests, the interfacial strength is between the strengths of the base alloys on the two sides, which confirms the reliable bonding ability achieved by this method. For the conical tube component with flange, the ultimate tensile strength of the combined-sintered part in 1000 ℃ is 406.7±3.2 MPa, and the ultimate strength of the pre-sintered part is 368.6±2.7 MPa, which are 39% and 26% higher than the strength of blade-like component prepared by casting and hot isostatic pressing (292 MPa). The proposed method discussed in our study can overcome the uneven density defects in HPS and achieve collaborative control of both the shape and performance when preparing a high height-to-thickness ratio or a complex-shaped close cross-section component.