中國有色金屬學報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 10 No. 2 April 2000 |
SU Jun-yi(蘇俊義)1, WOO Chung-Ho(胡仲豪)2
（1. School of Mechanical Engineering, Xi′an Jiaotong University, Xi′an 710049, P.R.China;
2. Department of Mechanical Engineering, Hong KongPolytechnic University, Hong Kong）
Abstract:A mixing microstructure containing Ni-based amorphous structures was observed by TEM in the laser clad zones. As the uniformity of chemical composition and temperature is poor in the laser cladding, the amorphous structure with some Ni3Al crystals coexists in the cladding. The microhardness of the mixing amorphous structure is HV 600~ 800, which is lower than that of crystal phases in the coating. Differential thermal analysis (DTA) shows that Ni-based amorphous structure exhibits a higher initial crystallizing temperature (about 588℃), which is slightly higher than that of the eutectic temperature of Al-Si alloy. The wear test results indicate that there are some amorphous structures in the laser clad coating, which reduces the peeling of the granular phases from matrix, and improves the wear resistance.
Key words: laser surface treatment; aluminum alloy; amorphous structures
