Sintering process in hot oscillatory pressure of 90W–7Ni–3Fe refractory alloy at different time

• Published in: Vacuum Vol. 195; p. 110697
• Main Authors: Zhao, Junliang, Gao, Ka, Liu, Dongyue, Ma, Tianyu, Sun, Dejian, Gao, Yang, Pan, Kunming, An, Linan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2022
• Subjects: Densification; Grain growth rate; Hot oscillating pressure; Sintering time; W–Ni–Fe refractory alloys; Sintering time; Hot oscillating pressure; Densification; Grain growth rate; W–Ni–Fe refractory alloys
• ISSN: 0042-207X; 1879-2715
• DOI: 10.1016/j.vacuum.2021.110697

90W–7Ni–3Fe refractory alloys were prepared by hot oscillating pressure (HOP) and hot pressuring (HP) under vacuum condition at different sintering time. Density, grain size and hardness of pure samples were measured to interpret the influence of sintering time on sintering process. Because of the increasing sintering time, the influence of sintering temperature and oscillating pressure was extended. In a shorter sintering time (about 1h), the densification rate was higher, the density increased fast, the grain growth was not obvious, and higher hardness was obtained. When the sintering time was longer (more than 1h), the densification rate was significantly reduced, and little improvement on density. At this process, the grain size was significantly increased, resulting in a decrease on hardness. However, though vacuum conditions avoid impurity elements, the measurement shows that above of HOP sample was always better than that of HP at a set value of sintering time. Whatever, these results demonstrated that HOP is a better technology to sintering refractory alloys compared with HP. [Display omitted] •Pure 90W–7Ni–3Fe samples were successfully fabricated by vacuum condition.•The effect of sintering time on hot oscillating pressure 90W–7Ni–3Fe refractory alloy was systematically firstly researched.•Fine grain and nearly full-density samples could be obtained by short sintering time and long time, respectively.•Densification curves and grain growth kinetics were used to understand the sintering process.•With the same performance, compared with HP, HOP is a more energy-saving sintering technology.