纳米TiO_2对微波法制备cBN陶瓷磨具的结构和性能影响

Effect of Nano TiO_2 on Structure and Properties of cBN Grinding Tools Prepared by Microwave Method

本实验选用SiO_2-Na_2O-Al_2O_3-B_2O_3系统作为基础陶瓷结合剂的烧结体系,向该体系中分别加入0. 2%、0.4%、0. 6%、0. 8%、1. 0%质量分数的纳米TiO_2制得纳米陶瓷结合剂。采用微波炉烧结方式,结合XRD分析、差热分析、抗弯强度和流动性检测分析,重点研究纳米TiO_2对陶瓷结合剂及c BN陶瓷磨具的影响。结果表明:添加纳米TiO_2后,陶瓷结合剂的流动性和抗弯强度得到明显改善。其中,加入0. 6%质量分数纳米TiO_2后,陶瓷模具的性能最佳,抗弯强度增大到28. 95 MPa,结合剂流动性增大到150. 6%。添加纳米TiO_2后,c BN陶瓷磨具的气孔率明显降低,抗弯强度显著提高。而且,纳米TiO_2的添加可实现结合剂对c BN磨粒的均匀包覆,改善其微观结构。

In this experiment,SiO 2-Na 2O-Al 2O 3-B 2O 3 system was used as the sintering system of basic vitrified bond.Nano vitrified bond was prepared by adding nano TiO 2 with mass fraction of 0.2%,0.4%,0.6%,0.8%and 1%to the basic vitrified bond system,respectively.Vitrified bond and cBN ceramic grinding tools were prepared by microwave sintering method.The effect of nano TiO 2 on vitrified bond and cBN ceramic grinding tools was mainly studied by XRD analysis,differential thermal analysis,bending strength and fluidity analysis.The results show that the fluidity and flexural strength of the vitrified bond are improved significantly after adding nano TiO 2.After adding 0.6%mass fraction of nano TiO 2,the ceramic grinding tools have the best performance,the bending strength is increased to 28.95 MPa and the bond fluidity is increased to 150.6%.After adding nano TiO 2,the porosity of cBN ceramic grinding tools decreases significantly,and the bending strength increases significantly.Moreover,the addition of nano TiO 2 can achieve the uniform coating of cBN particles and improve the microstructure of the grinding tools.