Corning Incorporated
CRACK-RESISTANT GLASS-CERAMIC ARTICLES AND METHODS FOR MAKING THE SAME

Abstract:

Glass-ceramics exhibiting a Vickers indentation crack initiation threshold of at least 15 kgf are disclosed. These glass-ceramics may be ion exchangeable or ion exchanged. The glass-ceramics include a crystalline and amorphous phases generated by subjecting a thin precursor glass article to ceramming cycle having an average cooling rate in the range from about 10.degree. C./minute to about 25.degree. C./minute. In one or more embodiments, the crystalline phase may comprise at least 20 wt % of the glass-ceramics. The glass-ceramics may include .beta.-spodumene ss as the predominant crystalline phase and may exhibit an opacity .gtoreq.about 85% over the wavelength range of 400-700 nm for an about 0.8 mm thickness and colors an observer angle of 10.degree. and a CIE illuminant F02 determined with specular reflectance included of a* between -3 and +3, b* between -6 and +6, and L* between 88 and 97.