球磨时间对自钝化钨合金的组织结构和抗氧化性能的影响  

Effect of ball milling time on microstructure and oxidation resistance of self-passivating W alloys

作　　者：陈时杰 叶超 柳炜 薛丽红[1] 周启来[2] 尹圣铭 严有为[1] CHEN Shijie;YE Chao;LIU Wei;XUE Lihong;ZHOU Qilai;YIN Shengming;YAN Youwei(State Key Laboratory of Materials Processing and Die and Mould Technology,Huazhong University of Science and Technology,Wuhan 430074,China;School of Materials Science and Engineering,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]华中科技大学材料科学与工程学院材料成形与模具技术国家重点实验室,武汉430074 [2]武汉理工大学材料科学与工程学院,武汉430070

出　　处：《复合材料学报》2023年第8期4531-4538,共8页Acta Materiae Compositae Sinica

基　　金：国家磁约束核聚变能发展研究专项(2018 YFE0306104);材料成形与模具技术国家重点实验室开放课题研究基金(P2023-024)。

摘　　要：自钝化W合金具有优异的抗高温氧化性能,可望用于高温环境中的关键部件。为了揭示合金的组织结构与高温抗氧化性能之间关系,采用机械合金化法结合放电等离子体烧结技术制备了自钝化W-Si合金,研究了不同机械合金化时间对合金显微组织结构的影响,并探究了合金的抗高温氧化性能。结果表明:合金由W、W_(5)Si_(3)和SiO_(x)组成,当球磨时间由4 h增加到20 h,合金中SiO_(x)的含量由16.2%增加到23.6%,而W_(5)Si_(3)的含量由57.8%降低到43.6%,且W和W_(5)Si_(3)的晶粒尺寸均减小,晶粒的细化有助于合金显微硬度的提高。在1000℃氧化10 h后,球磨4 h制得的合金增重为37.4 mg,而球磨20 h制得的合金增重达到了141.6 mg,它们的氧化层厚度分别约为167.0μm和415.7μm。球磨时间短制得的合金具有更优异的抗氧化性能,这是由于其W_(5)Si_(3)为连续相。W_(5)Si_(3)原位氧化形成的WO3/SiO2复合氧化物亦为连续相,形成了保护性氧化层,对合金的内氧化起到了有效的抑制作用。Self-passivating W alloys exhibit excellent high temperature oxidation resistance and are expected to be used in key components in high temperature environments.In order to reveal the relationship between the microstructure and high temperature oxidation resistance of the alloy,a self-passivating W-Si alloy was prepared by mechanical alloying method combined with spark plasma sintering.The effect of different mechanical alloying time on the microstructure of the alloy was studied.And the high temperature oxidation resistance of the alloys was investigated.The results show that the alloys are composed of W,W_(5)Si_(3)and SiO_(x)phases.When the ball milling time increases from 4 h to 20 h,the content of SiO_(x)in the alloys increases from 16.2%to 23.6%,while the content of W_(5)Si_(3) decreases from 57.8%to 43.6%,and the grain sizes of W and W_(5)Si_(3)are both reduced.The grain refinement contributes to the improvement of the microhardness of the alloys.After oxidized at 1000℃for 10 h,the mass gain of the alloy prepared by ball milling for 4 h is 37.4 mg,while that of the alloy prepared by ball milling for 20 h reaches141.6 mg,and their oxide layer thicknesses are about 167.0μm and 415.7μm,respectively.The alloy prepared with short ball milling time has better oxidation resistance,because the W_(5)Si_(3)in this alloy is a continuous phase.The WO_(3)/SiO_(2) composite oxide formed by in situ oxidation of W_(5)Si_(3)is also a continuous phase,forming a protective oxide layer and effectively inhibiting the internal oxidation of the alloy.

关 键 词：自钝化 W-Si合金 机械合金化 放电等离子体烧结 抗氧化性能 

分 类 号：TB331[一般工业技术—材料科学与工程]