CrMoNbTiV_(x)难熔高熵合金的组织特征及高温抗氧化性能  

Microstructure Characteristics and Oxidation Properties at Elevated Temperature for CrMoNbTiV_(x)Refractory High Entropy Alloys

作　　者：徐琴[1] 王琪 赵甲丁 殷亚军[3] 陈瑞润[2] Xu Qin;Wang Qi;Zhao Jiading;Yin Yajun;Chen Ruirun(School of Mechanic and Electrical Engineering,Henan University of Technology,Zhengzhou 450001,China;National Key Laboratory for Precision Hot Processing of Metals,Harbin Institute of Technology,Harbin 150001,China;State Key Laboratory of Materials Processing and Die&Mould Technology,School of Materials Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]河南工业大学机电工程学院,河南郑州450001 [2]哈尔滨工业大学金属精密热加工国家级重点实验室,黑龙江哈尔滨150001 [3]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,湖北武汉430074

出　　处：《稀有金属材料与工程》2024年第11期3194-3204,共11页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(52001114);河南省高校科技创新人才支持计划(23HASTIT022);华中科技大学材料成形与模具技术国家重点实验室开放基金(P2023-005);河南省高等学校青年骨干教师培育计划(2021GGJS064)。

摘　　要：制备了5种不同V含量的CrMoNbTiV_(x)(x=0,0.2,0.4,0.6,0.8)难熔高熵合金,研究了合金的相组成、微观组织特征及在800℃下的高温抗氧化性能。结果表明:不同V含量CrMoNbTiV_(x)合金在铸态时均为单一体心立方结构,形成了典型的枝晶状组织。在800℃氧化20和100 h后,CrMoNbTi合金的氧化增重分别为0.25和0.50 mg/cm^(2),CrMoNbTiV_(0.8)合金的氧化增重分别为1.49和3.36 mg/cm^(2)。随V含量的降低,CrMoNbTiV_(x)合金的氧化增重越少,氧化层表面越平整。CrMoNbTiV_(0.8)和CrMoNbTi合金氧化100 h后的表面高度差分别为24.80和3.37μm。V含量不同,合金的氧化产物也不相同,针状V_(2)Nb_(6)O_(19)氧化物显著降低CrMoNbTiV_(x)合金的抗氧化性能。V含量下降能促进氧化层中形成TiO_(2)、CrVNbO_(6)和Ti_(4)Cr_(3)Nb_(3)O_(2)致密氧化物,提高CrMoNbTiV_(x)难熔高熵合金高温抗氧化性能。随V含量减少,CrMoNbTiV_(x)合金氧化层中V_(2)Nb_(6)O_(19)、CrVNbO_(6)和V_(2)O_(5)含量均减少,不含V的CrMoNbTi合金氧化层由致密的TiO_(2)和Ti_(4)Cr_(3)Nb_(3)O_(2)组成,合金的抗氧化性能明显提高。CrMoNbTiV_(x)(x=0,0.2,0.4,0.6,0.8)refractory high entropy alloys with different contents of vanadium were prepared,and the phase constitution,microstructure characteristics and oxidation properties at elevated temperature of 800℃were investigated.Results show that the as-cast CrMoNbTiV_(x)alloys with different contents of vanadium exhibit single body-centered cubic(bcc)crystal and form dendrite structure.After oxidation at 800℃for 20 and 100 h,the mass gain of CrMoNbTi alloy is 0.25 and 0.50 mg/cm^(2),respectively,while the mass gain of CrMoNbTiV_(0.8)alloy is 1.49 and 3.36 mg/cm^(2),respectively.The mass gains of CrMoNbTiV_(x)alloys are decreased with decreasing the content of vanadium,and the surface of oxidation layer also gets smoother.The surface height differences of CrMoNbTiV_(0.8)and CrMoNbTi after oxidation for 100 h is 24.80 and 3.37μm,respectively.The oxidation products of alloys with different contents of vanadium are different,and the V_(2)Nb_(6)O_(19)needle shape oxidation products can obviously reduce the oxidation resistance properties of CrMoNbTiV_(x)alloys.Reducing the addition of vanadium can promote the formation of compact oxidation products of TiO_(2),CrVNbO_(6)and Ti_(4)Cr_(3)Nb_(3)O_(2),and therefore improve oxidation resistance properties of CrMoNbTiV_(x)alloys at elevated temperatures.V_(2)Nb_(6)O_(19),CrVNbO_(6)and V_(2)O_(5)in oxidation layer of CrMoNbTiV_(x)alloys are reduced with decreasing the content of vanadium.The oxidation layer of CrMoNbTi without addition of vanadium consists of compact TiO_(2)and Ti_(4)Cr_(3)Nb_(3)O_(2),and therefore the oxidation resistance is significantly improved.

关 键 词：难熔高熵合金 组织特征 相组成 抗氧化性能 高温 

分 类 号：TG132.32[一般工业技术—材料科学与工程]