溶胶-原位凝胶法制备金刚石/LZAS系陶瓷结合剂砂轮的结构与性能  

Microstructure and performance of LZAS vitrified bond/diamond grinding wheel by in-situ sol-gel method

作　　者：万隆[1,2] 张磊欣 刘小磐[1] 宋冬冬[1] 胡伟达[3] 周肖璇 

机构地区：[1]湖南大学材料科学与工程学院,长沙410083 [2]喷射沉积技术及应用湖南省重点实验室,长沙410083 [3]湖南工业大学冶金工程学院,株洲412007

出　　处：《粉末冶金材料科学与工程》2016年第6期939-945,共7页Materials Science and Engineering of Powder Metallurgy

基　　金：国家自然科学基金资助项目(No.51375157);湖南工业大学自然科学研究项目(2014HZX20)

摘　　要：以硝酸盐溶液、磷酸铵溶液、Si O2溶胶和金刚石颗粒制成混合料浆,经快速凝胶及干燥后,在850℃/1.5 h条件下烧结,得到金刚石/陶瓷结合剂复合体,通过对其微观结构以及表面粗糙度、抗弯强度和孔隙率等性能进行表征,研究混合料浆中的固相含量对金刚石/复合氧化物陶瓷复合体结构与性能的影响。结果表明:Si O2-Al2O3-Zn O-Na2O-Li2O-P2O5复合氧化物陶瓷结合剂的晶化程度高,晶型完整;随料浆中固含量增加,金刚石/陶瓷复合体的孔隙率先降低后升高,而抗弯强度则先升高后降低,当固含量(体积分数)为60%时,砂轮的孔隙率和抗弯强度分别达到最小值(26.2%)和最大值(69 MPa)。与传统粉末压制法制备的金刚石/复合陶瓷结合剂砂轮相比,采用溶胶-凝胶原位法制备的砂轮,结构均匀,抗弯强度和孔隙率分别提高约40.5%和34.8%,磨削加工的硬质合金工件表面无较深划痕,工件表面粗糙度为0.049μm。The ceramic vitrified bonded diamond grinding wheels were fabricated by in-situ sol-gel method and then sintered at 850 ℃ for 1.5h using a mixed slurry prepared by nitrite solution, SiO2 sol and diamond as raw materials. The effects of solid content on the microstructure and properties of vitrified bonded diamond grinding wheels were studied through characterizing the microstructure, surface roughness, bend strength and porosity. The results show that the SiO2- Al2O3-ZnO-Na2O-Li2O-P2O5 composite oxide ceramic vitrified bond gel exhibits high crystallization degree and the integrity crystal structure. With increasing solid content, the porosity of sintered body decreases first and then increases, while the bending strength changes in the opposite trend simultaneously. When the volume fraction of solid content is 60%, the porosity and the bending strength of sintered body reach the minimum value of 26.2% and the maximum value of 69 MPa, respectively. Compared to the traditional pressing method, the microstructure of grinding wheels prepared by in-situ sol-gel method is uniform and no deep scratches are observed on the polished surface of cemented carbide, resulting in a small surface roughness of 0.049 μm. Flexural strength and porosity are increased by about 40.5% and 34.8%, respectively.

关 键 词：溶胶-凝胶 金刚石 陶瓷结合剂 原位成形 微观结构 性能 

分 类 号：TG74[金属学及工艺—刀具与模具] TB332[一般工业技术—材料科学与工程]