VC添加量对WC-6%Co超细晶硬质合金微结构及性能的影响  

Effect of VC Addition on Microstructure and Mechanical Properties of Ultrafine Grained WC-6%Co Cemented Carbide

作　　者：曾惠钦 尹超[1,2] 毛善文[1,2] 曾瑞霖 Zeng Huiqin;Yin Chao;Mao Shanwen;Zeng Ruilin(State Key Laboratory of Cemented Carbide,Zhuzhou Hunan 412000,China;Zhuzhou Cemented Carbide Group Co.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]株洲硬质合金集团有限公司,湖南株洲412000

出　　处：《硬质合金》2023年第4期245-254,共10页Cemented Carbides

基　　金：国家重点研发计划(2022YFB3806702);湖南省十大技术攻关项目(2021GK1170)。

摘　　要：本文采用粉末冶金方法,在1450°C下烧结1h,制备了WC-6%Co-(0~1.0%)VC超细晶硬质合金,研究了VC添加量对WC平均晶粒尺寸和粒度分布、WC三维形貌及力学性能的影响。结果表明:随VC添加量的增加,WC-6%Co-VC超细晶硬质合金的WC平均晶粒尺寸先快速后缓慢减小,粒度分布不断变窄,硬度先快速后缓慢增加,而断裂韧性先快速后缓慢降低,抗弯强度先增加后急剧降低;添加0.25%VC后,WC形貌由截断三棱柱转变成台阶三棱柱,且随VC含量的增加,WC(0001)晶面上的台阶数量不断增加,台阶数量的增加会明显降低合金的断裂韧性和抗弯强度;WC-6%Co-0.25%VC硬质合金具有最优的综合性能,其维氏硬度、断裂韧性和抗弯强度分别为18.82GPa、8.87MPa·m^(1/2)和3190MPa。In this paper,WC-6%Co-(0~1.0%)VC ultrafine grained cemented carbide was prepared by sintering at 1450°C for 1 h using the powder metallurgy method.The effects of VC addition on the average grain size,particle size distribution,three-dimensional morphology,and mechanical properties of WC were studied.The results showed that with the increasing VC addition,the average grain size of WC decreased rapidly at first and then slowly,and the particle size distribution became narrower.The hardness of WC-6%Co-VC ultrafine grained cemented carbide increased rapidly first and then slowly,while the fracture toughness decreased rapidly first and then slowly,and the flexural strength increased first and then decreased sharply.With the addition of 0.25%VC,the WC morphology changed from a truncated triangular prism to a stepped triangular prism.With the increase in VC content,the number of steps on the WC(0001)crystal plane increased,and the increase in the number of steps would significantly reduce the fracture toughness and flexural strength of the alloy;WC-6%Co-0.25%VC cemented carbide had the best comprehensive properties,and its Vickers hardness,fracture toughness,and flexural strength were 18.82 GPa,8.87 MPa·m^(1/2),and 3190 MPa.

关 键 词：VC添加量 晶粒度分布 WC形貌 力学性能 

分 类 号：TG135.5[一般工业技术—材料科学与工程]