中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 34 No. 4 April 2024 |
（1. School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023, China;
2. Collaborative Innovation Center of New Nonferrous Metal Materials and Advanced Processing Technology, Luoyang 471023, China;
3. Research Institute of Special Steels, Central Iron and Steel Research Institute Company Limited, Beijing 100081, China;
4. State Key Laboratory of Laser Interaction with Matter, Northwest Institute of Nuclear Technology, Xi’an 710024, China;
5. Luoyang Ship Material Research Institute, Luoyang 471000, China）
Abstract:A high-strength Ni-W-Co-Ta medium-heavy alloy (MHA) was prepared through the melting–casting–forging followed by cryogenic rolling process. Detailed microstructure and mechanical property characterizations were conducted to unveil the influence of cyrorolling on Ni-W-Co-Ta MHA. The results revealed that initial equiaxial grains were elongated along the rolling direction firstly and then transformed to fibrous texture with increase in accumulated deformation, in which a large number of slip bands were generated to coordinate the intensive plastic deformation. A sharp increase in dislocation density significantly promoted the dislocation interactions, which, in turn, refined the grains down to nanometer scale. The strength and hardness increased significantly with the increase of the deformation, whereas the elongation decreased sharply. The fracture morphology changed from a typical ductile mode for the undeformed sample gradually to quasi-cleavage and ductile mixed mode for 90% deformed material.
Key words: Ni-W-Co-Ta medium-heavy alloys (MHAs); cryogenic rolling; fibrous texture; mechanical property; quasi-cleavage and ductile mixed fracture
