中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
Vol. 26 No. 4 April 2016 |
(Guangdong Provincial Key Laboratory of Metal Processing and Forming, School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640, China)
Abstract:Bimodal-grained Ti containing coarse and fine grains was fabricated by high-energy ball milling and spark plasma sintering (SPS). The microstructure and mechanical properties of the compacts sintered by Ti powders ball-milled for different time were studied. Experimental results indicated that when the ball-milling time increased, the microstructure of sintered Ti was firstly changed from coarse-grained to bimodal-grained structure, subsequently transformed to a homogeneous fine-grained structure. Compared with coarse-grained Ti and fine-grained Ti, bimodal-grained Ti exhibited balanced strength and ductility. The sample sintered from Ti powders ball-milled for 10 h consisting of 65.3% (volume fraction) fine-grained region (average grain size 1 μm) and 34.7% coarse-grained region (grain size > 5 μm) exhibited a compress strength of 1028 MPa as well as a plastic strain to failure of 22%.
Key words: titanium alloy; high-energy ball milling; spark plasma sintering; bimodal-grained structure