(华南理工大学 机电工程系， 广州 510640)
摘 要:
关键字: Co-C-Si合金； 相变； 相结构
（Mechanotronic Department, South China University of Technology，
Guangzhou 510640, P.R.China）
Abstract:The structure and phase transformation were investigated for Co72.7C11.8Si15.5 alloy homogenized at 1 000 ℃ for 7 d, then quenched in water by means of X-ray diffraction， TEM， FESEM and EP. The alloy consists of both hcp-Co as matrix (a =0.250 5 nm，c =0.407 3 nm) and hexagonal graphite as the second phase( a =0.246 5 nm， c =0.671 1 nm). No (200) reflection of fcc-Co high temperature phase is detected， which shows that the phase transformation from fcc to hcp has been completed, and the transformation temperature in equilibrium is over 1 000℃. Stable hcp-Co alloy is readily obtained by adding C and Si elements into Co metals.
Key words: Co-C-Si alloy； phase transformation； structure
