残余应力对涂覆Al_(2)O_(3)涂层的ZrO_(2)陶瓷的强度和裂纹扩展阻力的影响  

Effects of Residual Stresses on Strength and Crack Resistance in ZrO_(2) Ceramics with Alumina Coating

作　　者：李海燕 郝鸿渐 田远 汪长安[3] 包亦望 万德田 LI Haiyan;HAO Hongjian;TIAN Yuan;WANG Changan;BAO Yiwang;WAN Detian(China Building Material Test&Certification Group Co.,Ltd,Beijing 100024,China;State Key Laboratory of Green Building Materials,China Building Materials Academy,Beijing 100024,China;State Key Laboratory of New Ceramics and Fine Processing,School of Materials Science and Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]中国建材检验认证集团股份有限公司,北京100024 [2]中国建筑材料科学研究总院,绿色建材国家重点实验室,北京100024 [3]清华大学材料学院,新型陶瓷与精细工艺国家重点实验室,北京100084

出　　处：《无机材料学报》2022年第4期467-472,共6页Journal of Inorganic Materials

基　　金：National Natural Science Foundation of China (52032011);State Key Laboratory of New Ceramic and Fine Processing Tsinghua University (KF 202007);Youth Fund of China Building Materials Academy (ZD-16)。

摘　　要：本研究在ZrO_(2)基体表面涂覆一薄层Al_(2)O_(3)涂层,利用基体与涂层之间热膨胀系数不匹配,在Al_(2)O_(3)-ZrO_(2)预应力陶瓷(简称A_(C)Z_(S)预应力陶瓷)表层引入压应力。采用维氏压痕法评价残余应力对A_(C)Z_(S)预应力陶瓷的表层和基体中裂纹扩展阻力的影响。理论分析结合实验结果表明:表层的压应力使得A_(C)Z_(S)预应力陶瓷的裂纹扩展阻力增大,最终导致强度和损伤容限提高;且A_(C)Z_(S)预应力陶瓷表层的压应力和裂纹扩展阻力随着基体截面积与涂层截面积比值的增加而增大。当ZrO_(2)基体表层的Al_(2)O_(3)涂层厚度为40μm时,表层压应力使A_(C)Z_(S)预应力陶瓷的弯曲强度达到(1207±20)MPa,相比于同种工艺下制备的ZrO_(2)陶瓷强度提高了32%,同时也是Al_(2)O_(3)强度的3倍。此外,A_(C)Z_(S)预应力陶瓷也表现出很好的抗热震性能。By covering a thin Al_(2)O_(3) coating on ZrO_(2) substrate, compressive stress caused by the mismatch of thermal expansion coefficients between the coating and substrate was introduced in the surface layer of Al_(2)O_(3)-ZrO_(2) pre-stressed ceramics(marked as A_(C)Z_(S) pre-stressed ceramics). Vickers indentation test was carried out to check the crack resistance in the surface layer and substrate influenced by the residual stresses. The enhancement of the crack resistance in surface layer results in a high flexural strength and excellent damage tolerance. Both theoretical analysis and experimental results show that the compressive stress and crack resistance in the surface layer increase with the increasing ratio of the cross-sectional area of ZrO_(2) substrate to Al_(2)O_(3) coating. Due to the residual compressive stress existing in Al_(2)O_(3) coating, a high flexural strength of(1207±20) MPa was measured for ZrO_(2) specimens coated with 40 μm Al_(2)O_(3). The flexural strength is 32% higher than that of monolithic ZrO_(2), and about triple of the value of Al_(2)O_(3). Meanwhile, compared to ZrO_(2), the A_(C)Z_(S) pre-stressed ceramics exhibit superior thermal shock resistance.

关 键 词：Al_(2)O_(3)-ZrO_(2)预应力陶瓷 压应力 弯曲强度 损伤容限 

分 类 号：TQ174[化学工程—陶瓷工业]