摘要
利用预涂Si粉,Ti+Si粉的方法对TiAl合金进行电子束表面合金化,“原位”制得了以高硬度金属间化合物Ti_Si_3为增强相的表面改性层。利用光学显微镜、扫描电子显微镜、能谱仪及X射线衍射仪分析和研究了电子束表面改性层的显微组织结构；同时测试了沿改性层深度方向的硬度分布。结果表明,表面改性层由TiAl,Ti_3Al,Ti_Si_3相组成,Ti_5Si_3相的形态及分布沿层深呈均匀分布；改性层具有较高的显微硬度(HV),最高达895×9.8 MPa,约是基体的3倍。
This study is concerned with the microstructural analysis and the improvement of hardness of Si/TiAl surface composite coatings. “In-situ” composite coatings reinforced by Ti5Si3 intermetallic phase with high hardness have been fabricated on γ-TiAl substrates precoated with silicon, titanium ＋40% silicon powders by means of electron beam surface alloying. The microstructure characteristics of the composite coatings were investigated through OM, SEM, EDAX and XRD examination. Micro-hardness was measured from the surface down to the substrate by a Vickers hardness tester under a 1.96 N load. The results show that composite coatings consist of TiAl, Ti3Al and Ti5Si3 phases, the morphology and distribution of Ti5Si3 phase are homogeneous from the surface to the substrate. The hardness of the composite coatings is higher than that of the substrate, the maximum value reaches 895 × 9.8 MPa and is about triple that of the matrix.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2005年第12期1969-1973,共5页
Rare Metal Materials and Engineering
基金
国家863资助项目(2002AA724040)
