Na_2O/B_2O_3对陶瓷基础结合剂性能的影响

The Effect of Na_2O/B_2O_3 Molar Ratio on the Properties of Basic Vitrified Bonds

采用固相熔融法制备了Na_2O-B_2O_3-Al_2O_3-SiO_2系金刚石砂轮用陶瓷基础结合剂,考察了Na_2O与B_2O_3摩尔比对结合剂耐火度、流动性、气孔率、体积密度、抗折强度及显微结构的影响。结果表明,随着Na_2O与B_2O_3摩尔比升高,结合剂的耐火度降低、气孔率变化较小、流动性增强、体积密度增加、抗折强度先增加后减弱、显微结构也随之先致密后稀疏;当Na_2O与B_2O_3摩尔比为1.5时,结合剂综合性能最好,其抗折强度高达56 MPa,耐火度为720℃,流动性为190%;结合剂为非晶态结构,孔隙少,结构较致密,连接桥粗壮光滑。

The Na2O-B2O3-Al2O3-SiO2 basic vitrified bonds for diamond grinding wheels were prepared by the methods of solid phase melting, and the effects of Na2O/B2O3 ratio on the refractoriness, fluidity, porosity, bulk density, bending strength and microstructure were also investigated. Results indicated that the higher ratio of Na2O/B2O3 yielded the lower refractoriness and porosity and enhanced fluidity and bulk density. Meanwhile, the bending strength firstly increased, then decreased as the mierostrueture densified, and then loosened. Moreover, these vitrified bonds reached the parameter optimization with the bending strength of 56 MPa, the refractoriness of 720 ℃ and the fluidity of 190%. The mierostrueture of vitrified bonds showed the compact amorphous glass phase with the small and few pores, as well as the thick and smooth connection bridge.