Co-Ni-Al黏结相硬质合金的高温氧化行为研究  

High Temperature Oxidation Behavior of Cemented Carbide with Co-Ni-Al Binder Phase

作　　者：龙坚战[1,2,3] 徐涛 金鹏[1,3] 谭立群[3] Cao yu[2] 曾瑞霖[1,3] 袁觅文 魏修宇 Long Jianzhan;Xu Tao;Jin Peng;Tan Liqun;Cao Yu;Zeng Ruilin;Yuan Miwen;Wei Xiuyu(State Key Laboratory of Cemented Carbide,Zhuzhou Hunan 412000,China;Chalmers University of Technology,Gothenburg 41296,Sweden;Zhuzhou Cemented Carbide Group Corp.Ltd.,Zhuzhou Hunan 412000,China)

机构地区：[1]硬质合金国家重点实验室,湖南株洲412000 [2]Chalmers University of Technology,Gothenburg 41296,Sweden [3]株洲硬质合金集团有限公司,湖南株洲412000

出　　处：《硬质合金》2022年第5期398-408,共11页Cemented Carbides

基　　金：湖南创新型省份建设专项(2019GK2052);湖南省科技人才托举工程(2019TJ-Q02);株洲市科技重大专项(株科办[2021]53号)。

摘　　要：以传统粗晶WC-Co硬质合金为参照对象,研究了Co-Ni-Al黏结相硬质合金在空气中900℃的等温氧化行为。结果表明:随着黏结相含量的增加,合金的抗氧化性能提高;相同含量黏结相条件下,WC-Co-Ni-Al合金具有比WC-Co合金更好的抗氧化性;氧化过程因形成疏松的氧化层而出现膨胀现象,WC-Co合金氧化层主要由MeWO_(4)(Me=Co或Ni)钨酸盐和WO_(3)氧化物组成,而WC-Co-Ni-Al合金氧化层主要由MeWO_(4)钨酸盐、金属氧化物Me_(x)O_(y)(Me=Co、Ni或Al)和少量的WO_(3)氧化物组成。硬质合金的抗氧化性主要受氧化层/基体界面处的反应控制,Co-Ni-Al黏结相在选择性氧化过程中形成了更加致密的金属氧化物Me_(x)O_(y),该金属氧化物优异的抗氧化性阻碍了氧气向氧化层/基体界面的向内扩散,从而抑制了基体的进一步氧化,最终提高了WC-CoNi-Al硬质合金的抗氧化性。The isothermal oxidation behavior of cemented carbide with Co-Ni-Al binder phase in air at 900℃was studied and compared with the traditional coarse-grained cemented carbide using Co binder in this study.The results show that the oxidation resistance of the alloy is improved with the increase of binder phase content.In condition of the same content of binder phase,WC-Co-Ni-Al alloy has better oxidation resistance than WC-Co alloy.Expansion occurs due to the formation of a loose oxide layer during the oxidation process.The oxide layer of WC-Co alloy is mainly composed of MeWO_(4)tungstate and WO_(3)oxide,while the oxide layer of WC-Co-Ni-Al alloy is mainly composed of MeWO_(4)(Me=Co or Ni)tungstate,metal oxide Me_(x)O_(y)(Me=Co,Ni or Al)and a small amount of WO_(3)oxide.The oxidation of cemented carbide is mainly controlled by the reaction at the interface of the oxide layer and substrate,and the Co-Ni-Al binder phase forms a denser metal oxide during the selective oxidation process,which has excellent oxidation resistance.The inward diffusion of oxygen to the oxide layer/substrate interface is hindered by the denser metal oxide Me_(x)O_(y),thereby inhibiting further oxidation of the substrate,and consequently improving the oxidation resistance of WC-Co-Ni-Al cemented carbide.

关 键 词：Co-Ni-Al黏结相 硬质合金 氧化行为 氧化机理 

分 类 号：TG135.5[一般工业技术—材料科学与工程]