{"title":"Preparation and toughening mechanism of Al <sub>2</sub>O <sub>3</sub> composite ceramic toughened by B <sub>4</sub>C@TiB <sub>2</sub> core&ndash;shell units","authors":"Yingjie Shi, Weixing Li, Xiaorong Zhang, Jiachao Jin, Jilin Wang, Yu Dong, Jingbo Mu, Guangsuo Wang, Xiaoliang Zhang, Zhixiao Zhang","doi":"10.26599/jac.2023.9220826","DOIUrl":null,"url":null,"abstract":"In this paper, the concept of incorporating core–shell structured units as secondary phases to toughen Al<sub>2</sub>O<sub>3</sub> ceramics is proposed. An Al<sub>2</sub>O<sub>3</sub> composite ceramic toughened by B<sub>4</sub>C@TiB<sub>2</sub> core–shell units is successfully synthesized using a combination of molten salt methodology and spark plasma sintering. The synthesis of B<sub>4</sub>C@TiB<sub>2</sub> core–shell toughening units stems from the prior production of core–shell structural B<sub>4</sub>C@TiB<sub>2</sub> powders, and this core–shell structure is effectively preserved within the Al<sub>2</sub>O<sub>3</sub> matrix after sintering. The B<sub>4</sub>C@TiB<sub>2</sub> core–shell toughening unit consists of a micron-sized B<sub>4</sub>C core enclosed by a shell approximately 500 nm thick, composed of numerous nanosized TiB<sub>2</sub> grains. The regions surrounding these core–shell units exhibit distinct geometric structures and encompass multidimensional variations in phase composition, grain dimensions, and thermal expansion coefficients. Consequently, intricate stress distributions emerge, fostering the propagation of cracks in multiple dimensions. This behavior consumes a considerable amount of crack propagation energy, thereby enhancing the fracture toughness of the Al<sub>2</sub>O<sub>3</sub> matrix. The resulting Al<sub>2</sub>O<sub>3</sub> composite ceramics displays a relative density of 99.7±0.2%, a Vickers hardness of 21.5±0.8 GPa, and a fracture toughness 6.92±0.22 MPa·m<sup>1/2</sup>.","PeriodicalId":14862,"journal":{"name":"Journal of Advanced Ceramics","volume":null,"pages":null},"PeriodicalIF":18.6000,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Advanced Ceramics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.26599/jac.2023.9220826","RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, CERAMICS","Score":null,"Total":0}
引用次数: 0
Abstract
In this paper, the concept of incorporating core–shell structured units as secondary phases to toughen Al2O3 ceramics is proposed. An Al2O3 composite ceramic toughened by B4C@TiB2 core–shell units is successfully synthesized using a combination of molten salt methodology and spark plasma sintering. The synthesis of B4C@TiB2 core–shell toughening units stems from the prior production of core–shell structural B4C@TiB2 powders, and this core–shell structure is effectively preserved within the Al2O3 matrix after sintering. The B4C@TiB2 core–shell toughening unit consists of a micron-sized B4C core enclosed by a shell approximately 500 nm thick, composed of numerous nanosized TiB2 grains. The regions surrounding these core–shell units exhibit distinct geometric structures and encompass multidimensional variations in phase composition, grain dimensions, and thermal expansion coefficients. Consequently, intricate stress distributions emerge, fostering the propagation of cracks in multiple dimensions. This behavior consumes a considerable amount of crack propagation energy, thereby enhancing the fracture toughness of the Al2O3 matrix. The resulting Al2O3 composite ceramics displays a relative density of 99.7±0.2%, a Vickers hardness of 21.5±0.8 GPa, and a fracture toughness 6.92±0.22 MPa·m1/2.
期刊介绍:
Journal of Advanced Ceramics is a single-blind peer-reviewed, open access international journal published on behalf of the State Key Laboratory of New Ceramics and Fine Processing (Tsinghua University, China) and the Advanced Ceramics Division of the Chinese Ceramic Society.
Journal of Advanced Ceramics provides a forum for publishing original research papers, rapid communications, and commissioned reviews relating to advanced ceramic materials in the forms of particulates, dense or porous bodies, thin/thick films or coatings and laminated, graded and composite structures.