晶体取向对二硅酸锂玻璃陶瓷力学性能的影响OA

Objective:To investigate the effects of crystallographic orientation on the microstructure and mechanical properties of lithium disilicate glass-ceramics.Methods:Conventionally hot-pressed lithium disilicate glass-ceramics were set as the control group.Specimens were fabricated via conventional ECAP and modified ECAP with reduced-diameter channels,respectively.Specimens of each group were etched on longitudinal and transverse sections for microscopic morphological ob-servation.Hardness and fracture toughness were tested,and the anisotropy of crack propagation was analyzed.Results:The ECAP technique could effectively induce preferred crystal orientation,and specimens prepared by modified ECAP with re-duced-diameter channels exhibited superior consistency in crystallographic orientation.Compared with the conventional hot-pressed group,both types of ECAP-modified specimens achieved higher hardness(P<0.05),whereas their fracture toughness decreased(P<0.05).Conclusion:The modified ECAP process with reduced-diameter channels enables controllable regula-tion of crystallographic orientation in lithium disilicate glass-ceramics and effectively increases surface hardness.Crystal ori-entation governs the mechanical properties and crack propagation behavior of glass-ceramics.