Wear Resistance Of Glass-ceramic Composite Sheet

The glass-ceramic glaze produced by BODE incorporation in CaO-MgO-Al2O3-SiO2 system cannot meet the demands for abrasion resistance in public palce. With the appearance of scores in glaze surface, bad glossiness and decoration are generated. Through testing and analysising by XRD and SEM, reasons leading to poor abrasion resistance can be concluded as 1) low degree of crystallinity in glaze with more residuce glass and less crystal,2) precipitated phase in glaze are T-ZrO2 and M-ZrO2 with less amount and poor distribution, which cannot play the role of reinforcement.Inorder to improve usability of this product, suitable heat treatment can be employed, after which crystals can precipitated and abrasion resistance can be enhanced. After heat treatment at 980℃for 10min, a compact crystal layer about 20-30μm, consisted of Diopside and Feldspar soild solution, ia formed at the surface of glaze, making microhardness of glaze surface increased from 6.5GPa to 7.5GPa (increased 15%). Besides, additional compressive stress created in glaze surface also helps to improve abrasion resistance.By means of non-isothermal DSC technology, crystallization rate and active energy can be estimated. Computed results revealed that computed result related to heating rate. Maximum of crystallization increases and moves to higher temperature with the increasing heating rate. Active energy calculated through Kissinger, Ozawa, modified Kissinger and modified Ozawa equation is 328,348,464 and 457kJ/mol respectively.During the continual heating process, glaze behaves low crystallization rate while its surface crystallizes rapidly. Crystallization level can elevated by prolonging heat treatment time. On glaze surface, Diopside's precipitation takes place at glass-gas phase interface. Fine Diopside nucleuses grow in two dimension with increasing temperature. A compact crystal layer is formed when Diopside crystals contact with each other. However, inside glaze, Feldspar's precipitation takes place at glass-ziconia phase interface radially. When plate Feldspar precipitated, Diopside begins to precipitate on its surface. Further more, phase precipitated has some connection with heat history, cycle heat treatment makes glaze behave different from its behavior in continual heat treatment.