超细碳化钨基硬质合金的制备工艺研究.doc

PAGE  PAGE 28 2012届毕业生 毕业论文 题 目: 超细碳化钨基硬质合金的制备工艺研究 院系名称：材料科学与工程 专业班级： 磨专一班 学生姓名： 仝 浩 学 号：201126040124 指导教师： 卢新坡 教师职称： 年 月 日 摘 要 超细硬质合金具有高韧性、高耐磨性和高温强度，被广泛应用于切削工具、耐腐蚀工具、钻头、刀具、金属加工工具及耐磨部件等。超细钨粉和碳化钨粉是制造超细硬质合金的重要原料，烧结是硬质合金制备流程的最后一个关键步骤，烧结技术对硬质合金的性能具有最终的影响作用。碳含量、球磨时间，烧结工艺和晶粒长大抑制剂对超细硬质合金性能具有重要影响，通过研究确定如下制备综合性能优异的超细硬质合金工艺路线： 1、碳含量、抑制剂的种类及含量和烧结工艺超细硬质合金的性能影响较大。碳含量为5.2 %、添加0.4 %wt VC-0.4 %wt Cr3C2的抑制剂、采用1360℃低压真空烧结时，合金的综合性能最佳。 2、在添加 0.4 %wt VC-0.4 %wt Cr3C2的晶粒抑制剂，在 1360 ℃低压真空烧结下保温 120 分钟可以制备出晶粒度在 0.4 μｍ、洛式硬度为 HRA 93、强度为3320 MPa、组织均匀、无渗碳和脱碳相、综合性能优异的超细硬质合金。 关键词：超细硬质合金；碳化钨粉；制备工艺；烧结 Title:Process of preparation of ultrafine tungsten carbide base Abstract Ultrafine cemented carbide with high toughness, high wear resistance and high temperature strength , is widely used in cuttingTools , corrosion-resistant tools, drill bits , cutting tools , metalworking tools and wear-resistant parts. Ultrafine tungsten powder and tungsten carbide powder is an important raw material for the manufacture of ultra-fine cemented carbide , Sintered carbide is the last critical step in the preparation process , the performance of sintered carbide technology with the ultimate influence . Carbon content , milling time , sintering and grain growth inhibitors have a significant impact on the performance of ultra-fine cemented carbide , By following the preparation of a comprehensive study to determine the superior performance of ultra-fine carbide process route :1 , carbon content, type and content and sintering properties of ultrafine carbide inhibitors greater impact. A carbon content of 5.2 %, a 0.4% wt VC-0.4% wt Cr3C2 inhibitors using the 1360 ℃ low vacuum sintering , the best overall performance of the alloy .2 , adding 0.4% wt VC-0.4% wt Cr3C2 grains inhibitor sintered at 1360 ℃ under low pressure vacuum insulation 120 minutes can be prepared in grain size 0.4 μm, Rockwell hardness of HRA 93, strength