고에너지 전자빔 투사방법으로 제조된(TiC, SiC)/Ti-6Al-4V 표면복합재료의 미세조직과 마모 및 파괴특성(1. 미세조직 형성과정) = 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)

다국어 초록 (Multilingual 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.