Hf含量对CoCrFeNiHf_(x)共晶高熵合金显微组织与摩擦性能的影响  

Effect of Hf addition on microstructure and tribological properties of CoCrFeNiHfx eutectic high entropy alloys

作　　者：艾诚 赵鑫博 陈曦 郭敏[3] 黄太文[3] 刘林[3] AI Cheng;ZHAO Xin-bo;CHEN Xi;GUO Min;HUANG Tai-wen;LIU Lin(School of Materials Science and Engineering,Chang’an University,Xi’an 710064,China;Xi’an Saite Simai Titanium Industry Co.,Ltd.,Xi’an 710018,China;State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi’an 710072,China)

机构地区：[1]长安大学材料科学与工程学院,西安710064 [2]西安赛特思迈钛业有限公司,西安710018 [3]西北工业大学、凝固技术国家重点实验室,西安710072

出　　处：《中国有色金属学报》2023年第9期2850-2860,共11页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(51971174);中央高校基本科研业务费(300102311401,300102312407)。

摘　　要：本文设计了三种不同Hf含量的CoCrFeNiHf_(x)(x=0.3、0.43和0.5)共晶高熵合金,并探究了Hf含量对CoCrFeNiHf_(x)共晶高熵合金显微组织、显微硬度与摩擦学性能的影响规律。结果表明:随着Hf含量的提高,铸态组织由亚共晶(初生γ相+γ/Laves共晶相,x=0.3)向共晶(γ/Laves共晶,x=0.43)和过共晶(初生Laves相+γ/Laves共晶相,x=0.5)演变,且合金的显微硬度随之增大。纳米压痕实验结果表明,随着Hf含量的提高,合金中初生相和共晶相的硬度均随之增大。同时,Hf含量对摩擦因数的影响较小,但磨痕深度随Hf含量的增大呈先减小后增大的趋势,且合金的磨损机制由黏着磨损向磨粒磨损转变。共晶合金CoCrFeNiHf_(0.43)表现出最佳的耐磨性,其原因是共晶合金的片层状全共晶组织在磨损过程中发生了协同变形,使得该合金在磨损过程中不易产生脆性剥落。A series of CoCrFeNiHf_(x)(x=0.3,0.43 and 0.5)eutectic high entropy alloys with different Hf contents were designed,and the effects of Hf content on the microstructure,microhardness and tribological properties of CoCrFeNiHf_(x)eutectic high entropy alloys were investigated.With the increase of Hf content,the as-cast microstructures change from hypoeutectic(primaryγphase+γ/Laves eutectic phases,x=0.3)to eutectic(γ/Laves eutectic phases,x=0.43)and hypereutectic(primary Laves phase+γ/Laves eutectic phases,x=0.5).With the increase of Hf content,the microhardness of alloy increases and the friction coefficient remained almost does not change.The results of nanoindentation show that the hardness of both primary phase and eutectic phases in experimental alloys increase with the increase of Hf content.Meanwhile,the wear depth firstly decreases and then increases,and the wear mechanism changes from adhesive wear to abrasive wear.CoCrFeNiHf_(0.43)alloy shows the best wear resistance,which is caused by lamellar eutectic phases underwent synergistic deformation during wear process,and thus CoCrFeNiHf_(0.43)alloy is not prone to occur brittle spalling during wear.

关 键 词：CoCrFeNiHf_(x)共晶高熵合金 显微组织 显微硬度 纳米压痕 摩擦学性能 

分 类 号：TG113.2[金属学及工艺—物理冶金]