中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 17 No. 3 June 2007 |
（1. Department of Mechanical and Materials Engineering, China Three Gorges University, Yichang 443002, China;
2. State Key Laboratory of Powder Metallurgy, Central South University,
Changsha 410083, China;
3. State Key Laboratory of Die and Mould Technology,
Huazhong University of Science and Technology, Wuhan 430074, China）
Abstract: The influences of forming and sintering processes on distortion, cracking as well as mechanical properties of sintered bodies of ultrafine grained Ti(C, N)-based cermets were investigated. The results show that lubricant is indispensable to fabrication of ultrafine Ti(C, N)-based cermets, however, with low binder content in powder mixture, the lubrication action of paraffin is attenuated. A appropriate level of 2% (mass fraction) paraffin is determined for a cermet with binder content of 36% (mass fraction). It is also found that the influence of compaction pressure on distortion and cracking of sintered bodies presents a complex relationship. A relatively lower or higher compaction pressure, less than 100 MPa and more than 400 MPa respectively, favors uniform density distribution in green compact. The heating rate of sintering should be strictly controlled. Too fast heating rate results in enclosed pores to burst and forms large size pores in sintering body. A heating rate of 3 ℃/min is recommended.
Key words: Ti(C, N)-based cermet; ultrafine-grained structure; compacting; lubricant; sintering
