一种新型云母玻璃陶瓷的切削行为与显微结构

Cut Behavior and Microstructure of a Novel Mica Glass-ceramic

研制的材料在650℃晶化得到40％的云母晶体(其余为玻璃相)时,弯曲强度为150MPa,可在高速车削条件下形成连续的带状切屑,第一次在普通车削条件下使脆性的玻璃陶瓷材料表现出延性的材料去除模式.试验结果表明,脆性材料的延性切削模式的实现是由于云母晶体对裂纹走向的引导和玻璃相的强烈的剪切变形能力的共同作用.切削后,可在750℃再次晶化,随晶体体积份数的增加,弯曲强度提高到210MPa.

By optimizing the composition and microstructure, a new mica glass-ceramic with excellent machinability was obtained. For this kind of mica glass-ceramic, a continuous band chips can be formed in machining at a high velocity and cut depth after crystallizing at 650 degreesC and containing 40vol% of mica crystals (the rest is a glass phase), while the flexible strength reaches to 150MPa. The test results show that the mechanism of ductile-mode material removal of the brittle material is attributed to a combination of mica crystal guidance for crack propagation and the ability of glass phase to produce intense shearing strain. The further crystallizing at 750degreesC can enhance the flexible strength to 210MPa with increasing the amount of crystalline phase after cutting.