Preparation of ultra-fine grain W-Y2O3 alloy by an improved wet chemical method and two-step spark plasma sintering
Preparation of ultra-fine grain W-Y2O3 alloy by an improved wet chemical method and two-step spark plasma sintering
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DOI：
10.1016/j.jallcom.2016.11.364
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发表时间：
2017-02-25
影响因子：
6.2
通讯作者：
Liu, Yongchang
中科院分区：
文献类型：
--
作者：
Dong, Zhi;Liu, Nan;Liu, Yongchang
采用改进的化学法合成了Y2 O3掺杂钨复合粉体，创新性地采用了添加高分子表面活性剂聚乙烯吡咯烷酮（PVP，K17）和超声波处理的方法。因此，对于复合粉末前体，获得10.7nm的平均钨晶粒尺寸。为了抑制晶粒长大，采用两步放电等离子烧结（SPS）的粉末前驱体的固结。结果表明，在烧结态W-Y_2 O_3合金中，纳米（2-10 nm）和亚微米（100-300 nm）氧化物颗粒分别均匀地分散在钨晶粒内和钨晶界上。最终烧结温度为1400 ℃和1600 ℃的W-Y_2 O_3合金的平均钨晶粒尺寸分别为450和550 nm。两者都比以前的研究报告小得多。其相应的维氏显微硬度分别为543.2和729.1 Hv，也优于在以前的作品中获得的值。这些结果表明，采用改进的湿化学法结合超声处理和PVP添加是制备高性能超细晶氧化物弥散强化钨基合金的一种很有前途的方法。(C)© 2016 Elsevier B. V.版权所有。
The Y2O3 doped tungsten composite powder was synthesized via an improved chemical method where the polymeric surfactant Polyvinyl Pyrrolidone (PVP, K17) addition and ultrasonic treatment were both innovatively employed. Consequently, the average tungsten grain size of 10.7 nm was obtained for the composite powder precursor. To suppress the grain growth, two-step spark plasma sintering (SPS) was employed for the consolidation of powder precursor. It was found that in the sintered W-Y2O3 alloys, nano (2-10 nm) and submicron (100-300 nm) oxide particles were uniformly dispersed within tungsten grains and at tungsten grain boundaries, respectively. The average tungsten grain size of W-Y2O3 alloys whose final sintering temperature are 1400 and 1600 degrees C are 450 and 550 nm, respectively. Both of them are much smaller than that reported in previous studies. Their corresponding Vickers micro-hardness is 543.2 and 729.1 Hv, respectively, also better than the values obtained in previous works. These results indicate that the improved wet chemical method combined with ultrasonic treatment and PVP addition developed in our work is a promising way to fabricate high performance oxide-dispersion-strengthened tungsten based alloys with ultra-fine grain. (C) 2016 Elsevier B.V. All rights reserved.