| Title |
Effect of Heat Treatment on the Diffusion-Bonded Ni-Base Alloy Hastelloy X |
| Authors |
사인진(Injin Sah); 황종배(Jong-bae Hwang); 홍순익(Sun-ig Hong); 김응선(Eung-seon Kim); 김민환(Min-hwan Kim) |
| DOI |
https://doi.org/10.3365/KJMM.2017.55.2.115 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
metals; diffusion bonding; grain boundary; tensile test; hastelloy X |
| Abstract |
The effect of post-bond heat treatment (PBHT) on diffusion-bonded polycrystalline Ni-base alloy Hastelloy X (Ni-22Cr-18Fe-8Mo) was evaluated in this study. Diffusion bonding was conducted under a compressive pressure of 14 MPa in the temperature range of 1100-1200 ℃. While (Cr,Mo)-rich and (Mo,Si)-rich precipitates were developed along the interface at 1100 ℃, the precipitates were dissolved and grain boundary migration across the interface occurred above 1150 ℃. As the dissolution of precipitates is related to the temperature rather than compressive pressure, a modified diffusion bonding condition (1120 ℃/10 MPa) was applied. Brittle fracture with low tensile ductility was observed at the testing temperature of 700 ℃, but substantial recovery of ductility was achieved up to a testing temperature of 900 ℃ through PBHT (1180 ℃/1 h). The reduction of discontinuity at the interface was found to bring about the ductile behavior at high temperature. †(Received April 18, 2016; Accepted August 23, 2016) |