中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 27 No. 9 September 2017 |
（1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China; 2. School of Materials Science and Engineering, Central South University, Changsha 410083, China; 3. CNMC Albetter Albronze Co., Ltd., Liaocheng 252600, China）
Abstract:Cu-15Ni-8Sn-0.3Nb alloy rods were prepared by means of powder metallurgy followed by hot extrusion. Element maps obtained by electron probe micro analyzer (EPMA) showed that Nb-rich phases were formed and distributed within grains and at grain boundaries of the Cu-15Ni-8Sn-0.3Nb alloy. Transmission electron microscope (TEM) results indicated that there was no obvious orientation relationship between these phases and the matrix. Spinodal decomposition and ordering transformation appeared at early stages of aging at 400 °C and caused significant strengthening. Cu-15Ni-8Sn-0.3Nb alloy exhibited both higher strength (ultimate tensile strength >1030 MPa) and higher tensile ductility (elongation>9.1%) than Cu-15Ni-8Sn alloy after aging treatment. The improvement was caused by Nb-rich phases at grain boundaries which led o the refinement of grain size and postponed the growth of discontinuous precipitates during aging.
Key words: Cu-15Ni-8Sn-0.3Nb alloy; powder metallurgy method; hot extrusion; aging treatment; spinodal decomposition; microstructure; mechanical properties
