K2O-B2O3-Al2O3-SiO2-MgO-F系统可切削生物微晶玻璃

目的 可切削微晶玻璃的制备温度高达1500 ℃以上,此特性严重制约其产业化发展.本文设计制备了K2O-B2O3-Al2O3-SiO2-MgO-F系统低温云母生物微晶玻璃,并探讨制备工艺对材料结构和性能的影响.方法 采用1300 ℃熔化工艺与600～750 ℃晶化热处理工艺制备微晶玻璃,通过X射线衍射分析方法研究微晶玻璃的晶相组成,利用扫描电子显微镜观察微晶玻璃的形貌,并通过显微硬度分析、高速砂轮切削实验考察微晶玻璃的可切削性能.结果 分别经过600 ℃、650 ℃、700 ℃、750 ℃晶化热处理2 h、4 h、8 h后,玻璃中均形成了主晶相为氟金云母的微晶玻璃,微晶玻璃的显微硬度为3～8 GPa.且随着晶化温度的升高,微晶玻璃层状结构逐渐明晰,但硬度不断下降,其可切削性持续提高.结论 低温下熔化K2O-B2O3-Al2O3-SiO2-MgO系统玻璃工艺降低了可切削微晶玻璃的制备温度和成本,利于产业化生产和推广应用.

Machinable microcrystalline bioglass in K2O-B2O3-Al2O3-SiO2-MgO-F system

Objective The industrialization process of glass-ceramics has been restricted seriously because of high temperature above 1500 ℃ for preparation. A kind of low temperature bioglass containing mica was designed and fabricated based on K2 O- B203 - A1203 - SiO2- MgO- F system. Methods The samples wei：e made with melting procedure under 1300℃ and crystallizing procedure at 600- 750℃. The effects of preparation process on structures and properties of the glass were discussed. The crystalline compositions and morphologies were confirmed by X-ray diffraction （XRD） analysis and scanning electron microscopy （SEM） observation,and the microhardness as well as machinable properties was determined by microhardness analysis and high speed cutting tests simultaneously. Results The mica microcrystals as main crystalline phase were formed in all glasses while heated for 2 h,4 h and 8 h crystallization at 600℃ ,650 ℃ ,700℃and 750℃ respectively with 3- 8 GPa of microhardness values. As crystallizing temperature increasing, the layered structures were clear gradually, thus the microhardness declined continuous constantly ly. Concl and usions the machinability improved The preparation process based on K2O-B2O3-Al2O3- SiO2- MgO- F preparation temperature was pro industrialization and the application. S P ystem with itious to lower preparation temperature was propitious to the industrialization and the application.