晶粒长大抑制剂对超细硬质合金性能的影响
|
摘要
本文系统研究了晶粒长大抑制剂的种类、添加方式、添加量对WC-12％Co超细硬质合金性能的影响。按正交试验方法，设计了添加VC／Cr_3C_2及(TaNb)C／Cr_3C_2晶粒长大抑制剂制备超细硬质合金的试验方案，研究其对WC-12％Co超细硬质合金合金烧结特性、微观结构及合金性能的影响。
试验结果表明，同时添加多种晶粒长大抑制剂可抑制合金中的WC晶粒长大，并且对合金综合性能的提高更为有利，即实现高抗弯强度，高硬度的“双高”性能，其中，晶粒抑制剂含量为0.5％Cr_3C_2+0.2％VC时，制备的WC-12％Co超细硬质合金的抗弯强度达3786MPa，硬度为91.7HRA，WC平均晶粒度为0.6微米；晶粒抑制剂含量为0.3％Cr_3C_2+0.4％(TaNb)C时，制备的WC-12％Co超细硬质合金的抗弯强度达3790 MPa，硬度为91.6 HRA，WC平均晶粒度为0.8微米。真空／压力烧结工艺对含抑制剂的超细硬质合金综合性能的提高非常有利，对钴含量较低的合金更为明显。合金的扫描电镜及金相显微镜分析表明，用这种工艺制得的超细硬质合金孔隙度低(A_(02)，无脱碳相或游离碳组织缺陷，且WC晶粒分布均匀，无WC晶粒异常长大现象。超细硬质合金烧结特性试验证实，超细合金开始收缩的烧结温度及最大收缩率时的烧结温度均低于普通细颗粒硬质合金；添加晶粒抑制剂将阻碍超细晶硬质合金固相烧结时的致密化动力学过程，但使液相开始出现的温度有所降低。
文章还讨论了晶粒长大抑制剂在超细硬质合金烧结过程中的作用机理，认为晶粒抑制剂吸附在WC颗粒表面，阻碍了液相烧结时WC颗粒的溶解—析出过程，从而使WC晶粒得到细化。
In this paper, different content of mixed VC/Cr3C2 or (TaNb)C /Cr3C2 were added to WC-12%Co according to orthogonal experimental design. The effects of inhibitors on the sintering character, properties and microstructure of superfine cemented carbides are studied.
Results show that when different kinds of inhibitors are added at the same time in proper content, the alloys' WC grains are fined. They are helpful to enhance the properties of the alloys. When 0.5%Cr3C2/0.3% VC are added ,the bb of superfine grained hardmetal reaches 3786 MPa,the hardness is 91.7HRA and the alloys' WC grains are under 0.6 m. When 0.3% Cr3C2/0.4% (TaNb) C are added ,the bb of superfine grained hardmetals reach 3790 MPa, the hardness is 91.6 HRA and the alloys' WC grains are under 0.8 m and have no abnormal grains growth. The vacuum and HIP sintering process is very helpful to enhance properties of superfine cemented carbides with addition agent, especially for alloys with less Co , because vacuum and HIP sintering process can reduce alloys' porosity effectively .During the sintering process, the inhibitor will impede the densification of alloys' solid-phase sintering and decrease liquid occurrence temperature.
At last, the paper discusses the mechanisms of inhibitors on superfine grained cemented carbides in detail.
试验结果表明，同时添加多种晶粒长大抑制剂可抑制合金中的WC晶粒长大，并且对合金综合性能的提高更为有利，即实现高抗弯强度，高硬度的“双高”性能，其中，晶粒抑制剂含量为0.5％Cr_3C_2+0.2％VC时，制备的WC-12％Co超细硬质合金的抗弯强度达3786MPa，硬度为91.7HRA，WC平均晶粒度为0.6微米；晶粒抑制剂含量为0.3％Cr_3C_2+0.4％(TaNb)C时，制备的WC-12％Co超细硬质合金的抗弯强度达3790 MPa，硬度为91.6 HRA，WC平均晶粒度为0.8微米。真空／压力烧结工艺对含抑制剂的超细硬质合金综合性能的提高非常有利，对钴含量较低的合金更为明显。合金的扫描电镜及金相显微镜分析表明，用这种工艺制得的超细硬质合金孔隙度低(A_(02)，无脱碳相或游离碳组织缺陷，且WC晶粒分布均匀，无WC晶粒异常长大现象。超细硬质合金烧结特性试验证实，超细合金开始收缩的烧结温度及最大收缩率时的烧结温度均低于普通细颗粒硬质合金；添加晶粒抑制剂将阻碍超细晶硬质合金固相烧结时的致密化动力学过程，但使液相开始出现的温度有所降低。
文章还讨论了晶粒长大抑制剂在超细硬质合金烧结过程中的作用机理，认为晶粒抑制剂吸附在WC颗粒表面，阻碍了液相烧结时WC颗粒的溶解—析出过程，从而使WC晶粒得到细化。
In this paper, different content of mixed VC/Cr3C2 or (TaNb)C /Cr3C2 were added to WC-12%Co according to orthogonal experimental design. The effects of inhibitors on the sintering character, properties and microstructure of superfine cemented carbides are studied.
Results show that when different kinds of inhibitors are added at the same time in proper content, the alloys' WC grains are fined. They are helpful to enhance the properties of the alloys. When 0.5%Cr3C2/0.3% VC are added ,the bb of superfine grained hardmetal reaches 3786 MPa,the hardness is 91.7HRA and the alloys' WC grains are under 0.6 m. When 0.3% Cr3C2/0.4% (TaNb) C are added ,the bb of superfine grained hardmetals reach 3790 MPa, the hardness is 91.6 HRA and the alloys' WC grains are under 0.8 m and have no abnormal grains growth. The vacuum and HIP sintering process is very helpful to enhance properties of superfine cemented carbides with addition agent, especially for alloys with less Co , because vacuum and HIP sintering process can reduce alloys' porosity effectively .During the sintering process, the inhibitor will impede the densification of alloys' solid-phase sintering and decrease liquid occurrence temperature.
At last, the paper discusses the mechanisms of inhibitors on superfine grained cemented carbides in detail.
引文
[1] K. Schroeter. D. R. P. 420659, 1923
[2] 申带秀，李沐山．国内外硬质合金技术进展．稀有金属与硬质合金，1995，3：52～56
[3] 唐丹．关于硬质合金的最新动向．硬质合金，2001，1．18(1)：60～63
[4] Yakimune. Nippon Kyoukou Gakujutsu Ronbonshil, 1990, 98(5): 424
[5] 贾佐诚．超纸硬质合金的发展．硬质合金，2000，3：65～63
[6] Kenneth J A Brockes. Met powder Rep, 1989, 44(4): 281
[7] 黄忠耿．研制和生产粒度小于0.6微米碳化钨粉的工艺技术发展动态．1998，12，135：51～56
[8] Schubert W D, et al. In:Bildstein Hand Eck R eds. 13th International Plansee Siminar' 93, Proceedings. Wattens:RWF, Werbegessellschaftm. b. H., 1993:283
[9] Aceada N, et al. particle size of fine grain WC by the continuous direct carbonizing process MPR, Jan, 1990: 60
[10] Khaidaror V, et al. In:Bildstein Hand Eck Reds. 13th International Plansee Siminar' 93, Proceedings:RWF, Werbegessellschaft m. b. H., 1993:306
[11] 曹立宏，欧阳世翕，时东霞等．硬质合金WC-Co超细粉末的制备研究．硅酸盐学报，1996，10：604～607
[12] 硬质合金编写组．国外硬质合金．北京：冶金工业出版社，1976，138～139
[13] Zhou Zhiqiang. In:Bildstein H and Eck Reds. 12th International Plansee Siminar' 89, Proceedings. Insbruk:Verlangsanstalt Tyrolia, 1989:79
[14] 王国栋．硬质合金原理．北京：冶金工业出版社，1988：13～14
[15] Prakash L. J. Application of fine grained tungsten carbide based cemented carbides. Int of Refractory Metals & Hard Materials, 1995, 13: 257～264
[16] 王文光编译．超细晶粒硬质合金的特点及用途．工具展望，1998，4：8～10
[17] 唐远永．金属学原理(上册)．中南矿冶学院金属材料系，1981：155
[18] 张立．相图在硬质合金成分与工艺设计中的应用．硬质合金，2000，6：69～71
[19] Schubert W D, et al. In:Bildstein Hand Eck Reds. 13th International Plansee Siminar' 93, Proceedings. Wattens:RWF, Werbegessellschaft m. b. H., 1993:283
[20] L. Makhele-Lekala, S. Luyckx, et al. Semi-emprical relationship between the hardness, grain size and mean free path of WC-Co. Refractory Metals & Hard Materials, 2001:245～249
[21] B. Roebuck and M. G. Gee. Modelling the effects of structure size distribution on the strength and toughness of hardmetals. 14th International Plansee Siminar' 97, Proceedings. 1997:: 366～380
[22] Tanase T. Sintering of cemented carbide with vanadium. Metal Powder Report, 1998, 53(6):37
[23] 张荆门．硬质合金工业的进展．粉末冶金技术，2002，3：140～146
[24] 中国有色金属加工工业协会及中国钨协硬质合金分会．全国硬质合金行业2000年年鉴
[25] 罗重麟．钨添加剂对硬质合金性能和微观结构的影响．硬质合金，1984，2：15
[26] Aceada N, et al. particle size of fine grain WC by the continuous direct carbonizing process MPR, Jan, 1990: 60
[27] 余宗森，褚幼义．钢中稀土．北京：冶金工业出版社，1982：11～14
[28] 单世谨．稀有金属与硬质合金，1990，4：39～42
[29] 王笑天．金属材料学．北京：机械工业出版社，1982：11～14
[30] 史晓亮，段隆臣，汤凤林等．提高金刚石—硬质合金超硬复合体性能的研究．探矿工程(岩土钻掘工程)，2002，2：53～56
[31] 王社权．影响超细硬质合金性能的几个因素．硬质合金，2000，3：9～15
[32] 李沐山．八十年代世界硬质合金技术进展．《硬质合金》编辑部，1991：362
[33] M. Leiderman, O. Botstein, and A. Rosen. Sintering, microstructure, and properties of sub-micrometer cemented carbides. Powder Metallurgy, 1997:219～225
[34] Fukatsu T, et al. Int J Refract Met Hard Mater, 1991, 10(2): 57
[35] 金格瑞，W D．陶瓷导论．北京：中国建筑出版社，1979：474—479
[36] Schubert W D, Book A, Lux B. General aspects and limits of conventional and ultralfine WC powder manufacture and hard metal production. Int J of Refa Metals & Hard Mater, 1995, 13:281～296
[37] H. Ogawa and Y. Kataoka. High—Temp High—Press, 1981,13:481～494
[38] M. Leiderman, O. Botstein, and A. Rosen, Sintering, microstructure, and properties of sub-micrometer cemented carbides, Powder Metallurgy, 1997:219～22
[39] 株州硬质合金厂．硬质合金的生产．1994：251～252
[40] Silana Luyckx, Mohamed Zunaid Alli et al. Comparison between VC and Cr_3C_2 as grain refiners for WC—Co. Materials and Design, 2001, 22: 507～510
[41] T．Fukatsu等．1988年长沙第一届钨、钦、稀土和锑冶金和材料科学国际会议论文集，663
[42] F. Arenas, I. B. de Arenas et al. Influence of VC on the microstructure and mechanical properties of WC-Co sintered cemented carbides. Refractory Metals & Hard Materials, 1999:91～97
[43] 《国外硬质合金》编写组．国外硬质合金．冶金工业出版社，1976：480～501
[44] 刘寿荣，周金亭．TaC、Cr3C2对WC—Co硬质合金组织和性能的影响．硬质合金，1997，2：22～27
[45] A. Egami, M. Ehra et al. Morphology Of Vanadium Carbide In Submicron hardmetals, Proceedings Of 13th InternationalSeminar1993, 3: 639～648
[46] T. Yamamoto, Y. Ikuhara, T. Sakuma et al. High resolution transmission electron microscopy study in VC—doped WC—Co compound, Science and Technology of Advanced Materials, 2000, 1: 97～104
[2] 申带秀，李沐山．国内外硬质合金技术进展．稀有金属与硬质合金，1995，3：52～56
[3] 唐丹．关于硬质合金的最新动向．硬质合金，2001，1．18(1)：60～63
[4] Yakimune. Nippon Kyoukou Gakujutsu Ronbonshil, 1990, 98(5): 424
[5] 贾佐诚．超纸硬质合金的发展．硬质合金，2000，3：65～63
[6] Kenneth J A Brockes. Met powder Rep, 1989, 44(4): 281
[7] 黄忠耿．研制和生产粒度小于0.6微米碳化钨粉的工艺技术发展动态．1998，12，135：51～56
[8] Schubert W D, et al. In:Bildstein Hand Eck R eds. 13th International Plansee Siminar' 93, Proceedings. Wattens:RWF, Werbegessellschaftm. b. H., 1993:283
[9] Aceada N, et al. particle size of fine grain WC by the continuous direct carbonizing process MPR, Jan, 1990: 60
[10] Khaidaror V, et al. In:Bildstein Hand Eck Reds. 13th International Plansee Siminar' 93, Proceedings:RWF, Werbegessellschaft m. b. H., 1993:306
[11] 曹立宏，欧阳世翕，时东霞等．硬质合金WC-Co超细粉末的制备研究．硅酸盐学报，1996，10：604～607
[12] 硬质合金编写组．国外硬质合金．北京：冶金工业出版社，1976，138～139
[13] Zhou Zhiqiang. In:Bildstein H and Eck Reds. 12th International Plansee Siminar' 89, Proceedings. Insbruk:Verlangsanstalt Tyrolia, 1989:79
[14] 王国栋．硬质合金原理．北京：冶金工业出版社，1988：13～14
[15] Prakash L. J. Application of fine grained tungsten carbide based cemented carbides. Int of Refractory Metals & Hard Materials, 1995, 13: 257～264
[16] 王文光编译．超细晶粒硬质合金的特点及用途．工具展望，1998，4：8～10
[17] 唐远永．金属学原理(上册)．中南矿冶学院金属材料系，1981：155
[18] 张立．相图在硬质合金成分与工艺设计中的应用．硬质合金，2000，6：69～71
[19] Schubert W D, et al. In:Bildstein Hand Eck Reds. 13th International Plansee Siminar' 93, Proceedings. Wattens:RWF, Werbegessellschaft m. b. H., 1993:283
[20] L. Makhele-Lekala, S. Luyckx, et al. Semi-emprical relationship between the hardness, grain size and mean free path of WC-Co. Refractory Metals & Hard Materials, 2001:245～249
[21] B. Roebuck and M. G. Gee. Modelling the effects of structure size distribution on the strength and toughness of hardmetals. 14th International Plansee Siminar' 97, Proceedings. 1997:: 366～380
[22] Tanase T. Sintering of cemented carbide with vanadium. Metal Powder Report, 1998, 53(6):37
[23] 张荆门．硬质合金工业的进展．粉末冶金技术，2002，3：140～146
[24] 中国有色金属加工工业协会及中国钨协硬质合金分会．全国硬质合金行业2000年年鉴
[25] 罗重麟．钨添加剂对硬质合金性能和微观结构的影响．硬质合金，1984，2：15
[26] Aceada N, et al. particle size of fine grain WC by the continuous direct carbonizing process MPR, Jan, 1990: 60
[27] 余宗森，褚幼义．钢中稀土．北京：冶金工业出版社，1982：11～14
[28] 单世谨．稀有金属与硬质合金，1990，4：39～42
[29] 王笑天．金属材料学．北京：机械工业出版社，1982：11～14
[30] 史晓亮，段隆臣，汤凤林等．提高金刚石—硬质合金超硬复合体性能的研究．探矿工程(岩土钻掘工程)，2002，2：53～56
[31] 王社权．影响超细硬质合金性能的几个因素．硬质合金，2000，3：9～15
[32] 李沐山．八十年代世界硬质合金技术进展．《硬质合金》编辑部，1991：362
[33] M. Leiderman, O. Botstein, and A. Rosen. Sintering, microstructure, and properties of sub-micrometer cemented carbides. Powder Metallurgy, 1997:219～225
[34] Fukatsu T, et al. Int J Refract Met Hard Mater, 1991, 10(2): 57
[35] 金格瑞，W D．陶瓷导论．北京：中国建筑出版社，1979：474—479
[36] Schubert W D, Book A, Lux B. General aspects and limits of conventional and ultralfine WC powder manufacture and hard metal production. Int J of Refa Metals & Hard Mater, 1995, 13:281～296
[37] H. Ogawa and Y. Kataoka. High—Temp High—Press, 1981,13:481～494
[38] M. Leiderman, O. Botstein, and A. Rosen, Sintering, microstructure, and properties of sub-micrometer cemented carbides, Powder Metallurgy, 1997:219～22
[39] 株州硬质合金厂．硬质合金的生产．1994：251～252
[40] Silana Luyckx, Mohamed Zunaid Alli et al. Comparison between VC and Cr_3C_2 as grain refiners for WC—Co. Materials and Design, 2001, 22: 507～510
[41] T．Fukatsu等．1988年长沙第一届钨、钦、稀土和锑冶金和材料科学国际会议论文集，663
[42] F. Arenas, I. B. de Arenas et al. Influence of VC on the microstructure and mechanical properties of WC-Co sintered cemented carbides. Refractory Metals & Hard Materials, 1999:91～97
[43] 《国外硬质合金》编写组．国外硬质合金．冶金工业出版社，1976：480～501
[44] 刘寿荣，周金亭．TaC、Cr3C2对WC—Co硬质合金组织和性能的影响．硬质合金，1997，2：22～27
[45] A. Egami, M. Ehra et al. Morphology Of Vanadium Carbide In Submicron hardmetals, Proceedings Of 13th InternationalSeminar1993, 3: 639～648
[46] T. Yamamoto, Y. Ikuhara, T. Sakuma et al. High resolution transmission electron microscopy study in VC—doped WC—Co compound, Science and Technology of Advanced Materials, 2000, 1: 97～104