High Temperature Mechanical Properties of Ni3Al - 0.5 B Intermetallic compound Consolidated by P / M Methods
윤의한Eui Han Yoon, 황선근Sun Keun Hwang
Abstract
The effects of P/M processing methods on the mechanical properties of Ni₃Al-0.5 B intermetallic compound were studied. The major gases evolved during the degassing were water vapor and hydrogen. The density of experimental alloy was improved by hot isostatic pressing (HIP) following either reactive sintering (RS) or vacuum hot pressing (VHP); a full density was obtained by hot extruding (HE) elemental powder compacts. The ambient tensile yield strength, 840 MPa and elongation, 41% of hot extruded experimental alloys with 7㎛ grain sizes were superior to those of cast alloys found in the literature. However, the peak temperatures (T_P=400∼500℃) corresponding to the maximum yield strength of experimental alloys were lower than those (T_P=600℃ ) of cast alloys. The tensile characteristics of the experimental alloys were explained in terms of grain refinement, formation of γ+γ` duplex structure and a distribution of oxides.