(1. 中南大學(xué) 粉末冶金國(guó)家重點(diǎn)實(shí)驗(yàn)室,長(zhǎng)沙 410083;
2. 湘潭大學(xué) 機(jī)械工程學(xué)院,湘潭 411105;
3. 株洲鉆石切削刀具股份有限公司,株洲 412007)
摘 要: 通過配制不同碳含量的WC-6Co缺碳硬質(zhì)合金,采用X射線衍射、光學(xué)金相、顯微硬度、鈷磁和TRS等分析方法,對(duì)比研究碳含量對(duì)低壓燒結(jié)缺碳硬質(zhì)合金的顯微組織和性能的影響。結(jié)果表明:碳含量影響合金中η相的類型、含量、分布、WC的形狀以及合金的性能;Co3W3C相出現(xiàn)在缺碳程度相對(duì)較小的合金中,其含量隨碳含量的增加而增大,而Co6W6C相與之相反;合金中的η相總量隨碳含量的增大而減少;隨著缺碳程度的增加,合金中η相的分散均勻性變差,并且η相趨向于成大塊狀;WC大多呈現(xiàn)多角特征;合金的密度和維氏硬度隨著碳含量的增加,先大幅度增加后緩慢減小,碳含量為5.2%(質(zhì)量分?jǐn)?shù))時(shí)均出現(xiàn)最大值,合金的鈷磁和橫向斷裂強(qiáng)度隨著碳含量的增加而增加。
關(guān)鍵字: 硬質(zhì)合金;碳含量;η相;顯微組織
properties of carbon-deficient cemented carbides
(1. State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China;
2. School of Mechanical Engineering, Xiangtan University,Xiangtan 411105, China;
3. Zhuzhou Cemented Carbide Cutting Tools Co. Ltd.,Zhuzhou 412000, China)
Abstract:Effects of carbon content on microstructure and properties of WC-6Co carbon-deficient cemented carbides with carbon content from 5.0% to 5.6% prepared by sinter-HIP were analyzed by X-ray diffractometry, optical microscopy, Vickers hardness analysis, cobalt magnetic analysis, TRS and so on. The results show that, in carbon- deficient cemented carbides, carbon content affects the type, amount and distribution of η phase, WC shape and properties of alloys. Co3W3C phase appears in alloys with relative lower degree of carbon-deficient and whose amount increase with increasing carbon content, whereas Co6W6C phase varies reversely. The total amount of η phase decreases with increasing carbon content. With the increase of degree of carbon-deficient, the homogeneity of η phase distribution decreases, η phase tends to become clump shape and WC mostly maintains multangular character. In the field of research, the density and Vickers hardness of alloys substantially increase then slowly decrease with increasing carbon content and both appear maximum in 5.2% carbon(mass fraction), the cobalt magnetic and TRS of alloys increase with increasing carbon content.
Key words: cemented carbides; carbon content; η phase; microstructure


