Ning Han , Shoulei Yang , Shuyue Chen , Zhiyi Wang , Mengjie Yang , Lei Fan , Xiaoqing Guo , Yujin Dai , Yidan Wang , Shuangqing Chen , Zhengkai Zhang , Yun Zhang
{"title":"极限电流密度和电流阶跃率对闪速烧结 MgAl2O4 陶瓷微观结构和硬度的影响","authors":"Ning Han , Shoulei Yang , Shuyue Chen , Zhiyi Wang , Mengjie Yang , Lei Fan , Xiaoqing Guo , Yujin Dai , Yidan Wang , Shuangqing Chen , Zhengkai Zhang , Yun Zhang","doi":"10.1016/j.jeurceramsoc.2024.116982","DOIUrl":null,"url":null,"abstract":"<div><div>This study investigates the effects of limiting current density and current step rate on the microstructure and hardness of current-step flash-sintered (CS-FS) disc-shaped MgAl<sub>2</sub>O<sub>4</sub> ceramics. The results indicated that, unlike conventional flash sintering, the temperature of the sample during the current-step flash started at a lower initial value and subsequently increased gradually. Furthermore, the differences in oxygen vacancies between the positive and negative sides of the CS-FS-ed MgAl<sub>2</sub>O<sub>4</sub> ceramics were significantly reduced. This led to the CS-FS samples exhibiting higher relative density, finer grain size, a more uniform microstructure, and increased hardness. The homogeneous microstructure resulted in consistent hardness across both sides of each CS-FS-ed sample. Additionally, as the limiting current density increased, the grain sizes near the positive and negative sides gradually enlarged, while the relative density initially increased before decreasing. A similar trend was observed when the current step rate decreased.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 3","pages":"Article 116982"},"PeriodicalIF":5.8000,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Effects of limiting current density and current step rate on microstructure and hardness of flash sintered MgAl2O4 ceramics\",\"authors\":\"Ning Han , Shoulei Yang , Shuyue Chen , Zhiyi Wang , Mengjie Yang , Lei Fan , Xiaoqing Guo , Yujin Dai , Yidan Wang , Shuangqing Chen , Zhengkai Zhang , Yun Zhang\",\"doi\":\"10.1016/j.jeurceramsoc.2024.116982\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>This study investigates the effects of limiting current density and current step rate on the microstructure and hardness of current-step flash-sintered (CS-FS) disc-shaped MgAl<sub>2</sub>O<sub>4</sub> ceramics. The results indicated that, unlike conventional flash sintering, the temperature of the sample during the current-step flash started at a lower initial value and subsequently increased gradually. Furthermore, the differences in oxygen vacancies between the positive and negative sides of the CS-FS-ed MgAl<sub>2</sub>O<sub>4</sub> ceramics were significantly reduced. This led to the CS-FS samples exhibiting higher relative density, finer grain size, a more uniform microstructure, and increased hardness. The homogeneous microstructure resulted in consistent hardness across both sides of each CS-FS-ed sample. Additionally, as the limiting current density increased, the grain sizes near the positive and negative sides gradually enlarged, while the relative density initially increased before decreasing. A similar trend was observed when the current step rate decreased.</div></div>\",\"PeriodicalId\":17408,\"journal\":{\"name\":\"Journal of The European Ceramic Society\",\"volume\":\"45 3\",\"pages\":\"Article 116982\"},\"PeriodicalIF\":5.8000,\"publicationDate\":\"2024-10-11\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of The European Ceramic Society\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0955221924008550\",\"RegionNum\":2,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MATERIALS SCIENCE, CERAMICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of The European Ceramic Society","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0955221924008550","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, CERAMICS","Score":null,"Total":0}
Effects of limiting current density and current step rate on microstructure and hardness of flash sintered MgAl2O4 ceramics
This study investigates the effects of limiting current density and current step rate on the microstructure and hardness of current-step flash-sintered (CS-FS) disc-shaped MgAl2O4 ceramics. The results indicated that, unlike conventional flash sintering, the temperature of the sample during the current-step flash started at a lower initial value and subsequently increased gradually. Furthermore, the differences in oxygen vacancies between the positive and negative sides of the CS-FS-ed MgAl2O4 ceramics were significantly reduced. This led to the CS-FS samples exhibiting higher relative density, finer grain size, a more uniform microstructure, and increased hardness. The homogeneous microstructure resulted in consistent hardness across both sides of each CS-FS-ed sample. Additionally, as the limiting current density increased, the grain sizes near the positive and negative sides gradually enlarged, while the relative density initially increased before decreasing. A similar trend was observed when the current step rate decreased.
期刊介绍:
The Journal of the European Ceramic Society publishes the results of original research and reviews relating to ceramic materials. Papers of either an experimental or theoretical character will be welcomed on a fully international basis. The emphasis is on novel generic science concerning the relationships between processing, microstructure and properties of polycrystalline ceramics consolidated at high temperature. Papers may relate to any of the conventional categories of ceramic: structural, functional, traditional or composite. The central objective is to sustain a high standard of research quality by means of appropriate reviewing procedures.