The Effect of Isothermal Sintering Time on the Sintered Microstructure and Mechanical Properties of Ti-3Ni-(3-4)Si Alloys

摘要：

Additions of Si to Ti-Ni alloys can significantly enhance the sintering densification because Si decreases the solidus temperature of Ti-Ni alloys. However,the formation of Ti5Si3 networks along the grain boundaries is detrimental to the mechanical properties. An investigation has been made of the effect of the isothermal sintering time at 1250°C on the microstructure and mechanical properties of Ti-3Ni-(3-4)Si alloys. The sintered density increased with increasing sintering time in a narrow range from 99. 3％ to 100. 3％ theoretical density (TD) for Ti3Ni-4Si and from 97. 5％ to 99. 8％TD for Ti-3Ni-3Si. However, the distribution of the Ti5Si3 phase changed noticeably with increasing sintering time. When the isothermal sintering time was≤30 min,Ti5Si3 formed as isolated particles while continuous networks of Ti5Si3 developed along the grain boundaries at sintering times≥60 mia Tensile testing of Ti-3Ni-(3-4)Si alloys sintered at 1250℃ for 15,30,60 and 120 min revealed that the ultimate tensile strength (UTS) and elongation increased with sintering time and peaked at a sintering time of 30 min. The Ti-3Ni-4Si alloy produced slightly higher UTS (790 MPa) than the Ti-3Ni-3Si alloy (760 MPa) compared to 550 MPa for the Ti-3Ni alloy. The tensile elongations of Ti-3Ni-4Si and Ti-3Ni-3Si remained essentially the same (2. 5-3％) as that of Ti-3Ni in the absence of the networks of Ti5Si3.

关键词： Sintering titanium alloys silicon microstructure

作者: Y. F. Yang S. D. Luo G. B. Schaffer M. Qian

作者单位: The University of Queensland,School of Mechanical and Mining Engineering,ARC Centre of Excellence for Design in Light Metals,Brisbane,QLD 4072,Australia

会议类型: 国际会议

会议名称: The 12th World Conference Titanium(第十二届世界钛会 Ti-2011)

会议地点: 北京

会议语种:英文

页码: 1796-1799

在线出版日期: 2011-06-19（万方平台首次上网日期，不代表论文的发表时间）