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Vol.55, No.2, 115 ~ 125, 2017
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| Title |
| Effect of Heat Treatment on the Diffusion-Bonded Ni-Base Alloy Hastelloy X |
| 사인진 Injin Sah , 황종배 Jong-bae Hwang , 홍순익 Sun-ig Hong , 김응선 Eung-seon Kim , 김민환 Min-hwan Kim |
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| 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) |
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| Key Words |
| metals, diffusion bonding, grain boundary, tensile test, hastelloy X |
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