YG8硬质合金聚甲醛基黏结剂注射成形工艺的研究  

Injection Molding Process of YG8 Cemented Carbides with Paraformaldehyde-Based Binder

作　　者：何泽 袁建坤 杨宇 郎宏彬 原文 陈鹏起 程继贵[2,3] He Ze;Yuan Jiankun;Yang Yu;Lang Hongbin;Yuan Wen;Chen Pengqi;Cheng Jigui(Chengdu Bangpu Cutting Tools Co.,Ltd.,Chengdu Sichuan 611731,China;School of Materials Science and Engineering,Hefei University of Technology,Hefei Anhui 230009,China;Engineering Research Center of Powder Metallurgy of Anhui Province,Hefei Anhui 230009,China)

机构地区：[1]成都邦普切削刀具股份有限公司,四川成都611731 [2]合肥工业大学材料科学与工程学院,安徽合肥230009 [3]安徽省粉末冶金工程技术研究中心,安徽合肥230009

出　　处：《硬质合金》2023年第1期8-15,共8页Cemented Carbides

基　　金：成都市科技计划项目《新型硬质合金刀具研究开发》(2016-CP01-00055-GX);合肥工业大学科技开发项目《高性能硬质合金及不锈钢产品注射成形技术开发》(W2020JSKF0166)。

摘　　要：采用以聚甲醛(POM)为主要组元的多组元黏结剂,进行WC-8%Co(YG8)硬质合金注射成形。考察了注射温度、注射压力、保压压力等注射工艺参数对注射生坯组织性能的影响,在草酸气氛中对注射生坯进行催化脱脂后,在真空烧结炉中进行热脱脂和烧结。实验结果表明,在注射温度175℃、注射压力10 MPa、保压压力9 MPa、保压时间5 s、模温60℃的注射工艺下,可获得密度较高且无缺陷的注射生坯。在脱脂温度135℃、草酸气体通入速率10 g·min^(-1)、氮气通入速率50 mL·min^(-1)、脱脂时间8 h的催化脱脂工艺下,注射生坯中POM的脱除率可达到97%以上。在1420℃下真空烧结90 min,可获得相对密度超过99%、抗弯强度和硬度HRA分别达1872 MPa、89.5,钴磁为7.2%的YG8硬质合金烧结体。This study carried out injection molding of WC-8%Co(YG8) cemented carbide by use of a multi-component binder with polyoxymethylene(POM) as the main component. It investigated the effects of injection process parameters such as injection temperature, injection pressure, and holding pressure on the microstructure and properties of green compacts.In addition, the green compacts underwent catalytic debinding in an oxalic acid atmosphere, and then they were thermally debinded and sintered in a vacuum sintering furnace. The results show that under the injection temperature of 175 ℃,injection pressure of 10 MPa, holding pressure of 9 MPa, holding time of 5 s, and mold temperature of 60 ℃, defect-free green compacts with high density can be obtained. Under the catalytic debinding process with a debinding temperature of135 ℃, an oxalic acid gas influx rate of 10 g·min^(-1), a nitrogen gas influx rate of 50 mL·min^(-1), and a debinding period of 8 h,more than 97% of POM can be debinded from the green compacts. Sintered YG8 cemented carbide compacts can be obtained by vacuum sintering of the debinded green compacts at 1420 ℃ for 90 min, with relative density above 99%,transverse rupture strength of 1872 MPa, hardness of 89.5 HRA, and cobalt magnetism of 7.2%.

关 键 词：WC-8%Co硬质合金 注射成形 聚甲醛 催化脱脂 

分 类 号：TF125.3[冶金工程—粉末冶金]