WMoNbCrTi高熵合金的力学性能及其渗硅后的氧化行为  

Mechanical properties of WMoNbCrTi HEA and its oxidation behavior after siliconizing

作　　者：颜建辉 张孝蹯[1] 汪异 邱敬文 YAN Jian-hui;ZHANG Xiao-fan;WANG Yi;QIU Jing-wen(School of Materials Science and Engineering,Hunan University of Science and Technology,Xiangtan 411201,China;Hunan Provincial Key Defense Laboratory of High Temperature Wear Resisting Materials and Preparation Technology,Hunan University of Science and Technology,Xiangtan 411201,China)

机构地区：[1]湖南科技大学材料科学与工程学院,湖南湘潭411201 [2]湖南科技大学高温耐磨材料及制备技术湖南省国防科技重点实验室,湖南湘潭411201

出　　处：《材料热处理学报》2022年第5期62-70,共9页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(52175167);湖南省自然科学基金(2020JJ4025)。

摘　　要：高比重难熔高熵合金作为一种高温结构材料有较好的应用前景,轻量化设计和抗氧化性能的提高对难熔高熵合金的实际应用非常重要。在高比重WMoNb合金基体中加入金属Cr和Ti元素,设计并制备了一种等摩尔比的WMoNbCrTi高熵合金,并采用固态渗Si在其表面制备了一层多元硅化物涂层。结果表明:以W、Mo、Nb、Cr和Ti粉末为原料,通过机械合金化成功制备了BCC结构的固溶体合金粉末,放电等离子烧结后高熵合金的组织主要由BCC固溶体和Laves相组成。WMoNbCrTi高熵合金的硬度和压缩断裂强度分别为973 HV20和2241 MPa,这主要归因于Laves相的弥散强化、BCC固溶体的固溶强化及其晶粒细化。具有(W, Mo, Nb, Cr, Ti)Si_(2)多元渗硅层的高熵合金在1200℃氧化100 h后增重仅为0.44 mg·cm^(-2),渗硅层有效改善了WMoNbCrTi高熵合金的抗高温氧化性能,归因于渗硅层表面生成了一层致密连续的氧化膜。Refractory high entropy alloy(HEA) with high specific gravity elements has an excellent application prospect as a high temperature structural material. The lightweight design and the improvement of oxidation resistance are very important for the practical application of refractory high entropy alloy. A WMoNbCrTi high entropy alloy with equal molar ratio was designed and prepared by adding metal elements Cr and Ti into the matrix of high specific gravity WMoNb alloy, and a layer of multicomponent silicide coating was prepared on its surface by solid infiltration of Si. The results show that the solid solution alloy powder with body-centered cubic(BCC) structure is successfully prepared by mechanical alloying with W, Mo, Nb, Cr and Ti powders as raw materials, and the microstructure of the high entropy alloy prepared by spark plasma sintering using the alloy powder as raw materials is mainly composed of BCC solid solution and Laves phase. The hardness and compressive fracture strength of the WMoNbCrTi high entropy alloy are 973 HV20 and 2241 MPa, respectively, which is mainly due to the dispersion strengthening of Laves phase, and the solution strengthening and grain refinement of BCC solid solution. The mass gain of the WMoNbCrTi high entropy alloy with(W, Mo, Nb, Cr, Ti) Si_(2) multicomponent siliconized layer is only 0.44 mg·cm^(-2) after oxidation at 1200 ℃ for 100 h. The siliconized layer effectively improves the high temperature oxidation resistance of the WMoNbCrTi high entropy alloy, which is attributed to the formation of a dense and continuous oxidation film on the surface of the siliconized layer.

关 键 词：WMoNbCrTi高熵合金 等离子烧结 力学性能 渗硅 抗氧化性能 

分 类 号：TG146.[一般工业技术—材料科学与工程]