摘要
采用非自耗真空熔炼炉制备了一组非等摩尔比的高熵合金(NiAl)_(63-x)V_(20)Cr17B_(x)(x=0、0.2、0.4、0.6、0.8和1.0,摩尔比),通过XRD、EPMA、万能材料试验机等手段研究了B含量对合金微观组织和力学性能的影响。结果表明,(NiAl)_(63)V_(20)Cr_(17)合金为B2+BCC双相共晶结构,属于海藻状共晶枝晶,规则的片层共晶被不规则的片层共晶包围。随着B含量增加,(NiAl)_(63-x)V_(20)Cr_(17)Bx合金的微观结构由片层状共晶结构(x=0)转变为亚共晶结构(x>0.4),纳米沉淀物(含M_(2)B化合物)在初生相上析出。合金硬度先增加后减小,断裂强度和断裂应变持续增大。当x=0.8时,高熵合金具有良好的综合力学性能,其硬度(HV)为556,屈服强度为1 523 MPa,断裂强度为3 348 MPa,断裂应变为34.5%。
A non-equiatomic(NiAl)_(63-x)V_(20)Cr_(17)B_(x) eutectic high-entropy alloy was prepared by non-self-consumable vacuum melting furnace, and effects of B on microstructure and mechanical properties of alloys were investigated by means of XRD, EPMA, and universal experimental machine. The results indciate that(NiAl)_(63)V_(20)Cr_(17) alloy is composed of B2+BCC dual-phase eutectic structure, which belongs to seaweed-like eutectic dendrites with regular lamellar eutectic surrounded by irregular lamellar eutectic. With the increase in B content, the microstructure of(NiAl)_(63-x)V_(20)Cr_(17)B_(x) alloys is transformed from the lamellar eutectic structure(x=0) to hypoeutectic structure(x>0. 4), and nanoprecipitates(containing M2B compounds) are generated on primary phase. The hardness of alloy is increased and then decreased, and the fracture strength and fracture strain continue to be increased. When x=0. 8, the high entropy alloy exhibits desirable comprehensive mechanical properties, where the hardness, yield strength, fracture strength and fracture strain reach 556 HV, 1 523 MPa, 3 348 MPa and 34. 5%, respectively.
作者
方东
张安
罗爱娇
雷浩锋
李波
赵光伟
叶喜葱
Fang Dong;Zhang An;Luo Aijiao;Lei Haofeng;Li Bo;Zhao Guangwei;Ye Xicong(Hubei Engineering Center of Graphite Additive Manufacturing Technology and Equipment,China Three Gorges University,Yichang 443002;College of Mechanical and Power Engineering,China Three Gorges University,Yichang 443002;Zhejiang Zhengxin Vehicle Testing Co.,Ltd.,Wenzhou 325400)
出处
《特种铸造及有色合金》
CAS
北大核心
2024年第1期30-35,共6页
Special Casting & Nonferrous Alloys
基金
三峡大学石墨增材制造技术与装备湖北省工程研究中心开放基金资助项目(HRCGAM202101)
2022年产业技术基础公共服务平台资助项目(2022-232-223)。
关键词
高熵合金
共晶合金
显微组织
力学性能
High Entropy Alloy
Eutectic Alloy
Microstructure
Mechanical Property
