氧化锆质量分数对牙科复相铝瓷强度和断裂韧性的影响  

Effect of Zirconia Content on Flexural Strength and Fracture Toughness of Dental Zirconia Toughened Composite Alumina Ceramic

作　　者：赵克[1] 张新平[2] 李湘霞[1] 朱文军[1] 

机构地区：[1]中山大学光华口腔医学院.附属口腔医院修复科,广东广州510055 [2]华南理工大学机械工程学院材料科学与技术研究所,广东广州510640

出　　处：《华西口腔医学杂志》2007年第3期295-298,共4页West China Journal of Stomatology

基　　金：中国博士后科学基金资助项目(200114)

摘　　要：目的测定所制备的牙科氧化锆增韧复相铝瓷(ZTCA)的力学性能,探讨氧化锆质量分数变化对ZTCA力学性能的影响及其增韧机制。方法溶胶-凝胶法制备单相Al2O3粉体,表面诱导沉淀法制备4组不同ZrO2质量分数的ZTCA粉体。将5组粉体干压成型后烧结并加工成标准试件用于力学性能试验,测定三点弯曲强度及断裂韧性;扫描电子显微镜观察基体断口形貌;X射线衍射分析ZTCA基体晶相组成。结果ZTCA抗弯强度随ZrO2的增加先上升而后下降;ZrO2加入量为30%时,抗弯强度最高,为304.5MPa,对应的断裂韧性为1.85MPa·m1/2;ZTCA基体晶相包括α-Al2O3、四方相氧化锆以及少量的单斜相氧化锆。结论ZrO2质量分数不同对应ZTCA的强韧化机制不同,ZrO2质量分数为15%～30%时,材料以应力诱导相变增韧为主;ZrO2质量分数大于30%时,还存在微裂纹增韧机制。Objective To evaluate mechanical properties of zirconia toughened composite alumina （ZTCA） ceramic used for dental application, characterize the effect of different zirconia contents on mechanical properties of ZTCA. Methods Dental alumina ceramic powder was prepared by sol-gel method, and four groups of ZTCA powders with different zirconia contents were prepared via surface-induced precipitation method. All five groups of powders were dry-pressed and then sintered to make standard specimens for mechanical tests. The flexural strength and fracture toughness of these specimens were evaluated, and the fractography was characterized by scanning electronic microscope （SEM）. Phases of ZTCA were also determined using X-ray diffraction （XRD）. Results It was found that the flexural strength of ZTCA ceramics increases with ZrO2 content up to 30%, and decreases thereafter. ZTCA specimens containing 30% ZrO2 show the highest flexural strength, and the corresponding fracture toughness was 1.85 MPa·m^1/2. The XRD results of ZTCA ceramics showed the phase constituents of α-Al2O3, t-ZrO2 and a small amount of m-ZrO2. Conclusion The strengthening and toughening mechanisms of ZTCA depend on ZrO2 content. In the range of 15%-30% ZrO2, the stress-induced phase transformation toughening mechanism is dominant, while microcrack and deflection exist as the additional toughening mechanism when ZrO2 addition amount is above 30%.

关 键 词：牙瓷料 氧化锆 抗弯强度 断裂韧性 

分 类 号：R783.1[医药卫生—口腔医学]