| Title |
Microstructure, Wear Resistance, and Fracture Properties of (TiC, SiC)/Ti-6Al-4V Surface Composites Fabricated by High-Energy Electron Beam Irradiation (Part 1. Formation Process of Microstructure) |
| Authors |
오준철(Jun Cheol Oh); 윤은섭(Eun Sub Yun); 이성학(Sung Hak Lee) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
Surface composite; Electron beam irradiation; Ti-6Al-4V; TiC; SiC; Flux; Microstructure |
| Abstract |
The present study is concearned with microstructural analysis of (TiC, SiC)/Ti-6Al-4V surfaces composites fabricated by high-energy electron beam irradiation. The mixtures of TiC, SiC, Ti+SiC, and TiC+SiC powders and CaF_2 flux were evenly deposited on a Ti-6Al-4V substrate, and then electron beam was irradiated on these mixtures using an electron beam accelerator. In the specimens processed with flux addition, the surface-alloyed layers of 1.2∼2.1 ㎜ in thickness were homogeneously formed without defects, and contained a large amount (30∼66 vol.%) of precipitates such as TiC and Ti_5Si_3 in the martensitic matrix. Upon electron beam irradiation, (TiC, SiC)/flux powder mixtures and part of the substrate were melted to form a molten metal containing Ti, Si, and C. Here, C and Si atoms interacted with Ti atoms to form TiC and Ti_5Si_3, respectively, and the matrix was composed of martensite because of fast cooling during solidification. Microstructural modifications including melting, solidification, precipitation, and phase transformation processes could be explained well from a Ti-Si-C ternary phase diagram. |