Yuchi Wang , Yuchu Wang , Chaoyi Liu , Jinwoo Hwang , Yue Fan , Yunzhi Wang
{"title":"大块金属玻璃变形行为的原子信息中尺度建模","authors":"Yuchi Wang , Yuchu Wang , Chaoyi Liu , Jinwoo Hwang , Yue Fan , Yunzhi Wang","doi":"10.1016/j.actamat.2024.120136","DOIUrl":null,"url":null,"abstract":"<div><p>Both atomistic and mesoscale simulation techniques have been extensively employed to gain fundamental understanding of the structures, deformation mechanisms, and structure-property relationships in bulk metallic glasses (BMGs), each with its unique strengths and limitations. Nevertheless, there is a limited degree of synergistic integration between the two approaches. In this study, we extract key properties of shear transformation zones (STZs) directly from the atomistic simulations, including their size, number of shear modes, eigenstrain, and most importantly, the activation energy barrier spectrum as a function of cooling history and strain rate. We then incorporate these STZ properties into a heterogeneously randomized STZ dynamic model implemented in a kinetic Monte Carlo algorithm to study parametrically the deformation microstructure, shear band formation and stress-strain behavior of BMGs. Two important characteristics of STZ activation that dictate the strength and ductility of a glass are identified. One is the average of the activation energy barrier spectrum (approximated by a Gaussian distribution), determined by the glass composition and processing history such as the cooling rate. The other is the amount of shift of the Gaussian distribution towards smaller activation energy barrier values during deformation, which is determined by the initial structural states and strain rate during deformation, and exhibits a saturation value. These findings have allowed us to gain important fundamental insights into the correlation between the degree of shear-induced softening and the general deformation behavior of BMGs, leading to a better understanding of the correlation between the processing history/loading condition and the mechanical behavior.</p></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":null,"pages":null},"PeriodicalIF":8.3000,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1359645424004877/pdfft?md5=c8e3c8712e17e521db5aebd050e4f390&pid=1-s2.0-S1359645424004877-main.pdf","citationCount":"0","resultStr":"{\"title\":\"Atomistically informed mesoscale modelling of deformation behavior of bulk metallic glasses\",\"authors\":\"Yuchi Wang , Yuchu Wang , Chaoyi Liu , Jinwoo Hwang , Yue Fan , Yunzhi Wang\",\"doi\":\"10.1016/j.actamat.2024.120136\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Both atomistic and mesoscale simulation techniques have been extensively employed to gain fundamental understanding of the structures, deformation mechanisms, and structure-property relationships in bulk metallic glasses (BMGs), each with its unique strengths and limitations. Nevertheless, there is a limited degree of synergistic integration between the two approaches. In this study, we extract key properties of shear transformation zones (STZs) directly from the atomistic simulations, including their size, number of shear modes, eigenstrain, and most importantly, the activation energy barrier spectrum as a function of cooling history and strain rate. We then incorporate these STZ properties into a heterogeneously randomized STZ dynamic model implemented in a kinetic Monte Carlo algorithm to study parametrically the deformation microstructure, shear band formation and stress-strain behavior of BMGs. Two important characteristics of STZ activation that dictate the strength and ductility of a glass are identified. One is the average of the activation energy barrier spectrum (approximated by a Gaussian distribution), determined by the glass composition and processing history such as the cooling rate. The other is the amount of shift of the Gaussian distribution towards smaller activation energy barrier values during deformation, which is determined by the initial structural states and strain rate during deformation, and exhibits a saturation value. These findings have allowed us to gain important fundamental insights into the correlation between the degree of shear-induced softening and the general deformation behavior of BMGs, leading to a better understanding of the correlation between the processing history/loading condition and the mechanical behavior.</p></div>\",\"PeriodicalId\":238,\"journal\":{\"name\":\"Acta Materialia\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":8.3000,\"publicationDate\":\"2024-06-26\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.sciencedirect.com/science/article/pii/S1359645424004877/pdfft?md5=c8e3c8712e17e521db5aebd050e4f390&pid=1-s2.0-S1359645424004877-main.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Acta Materialia\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S1359645424004877\",\"RegionNum\":1,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MATERIALS SCIENCE, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Acta Materialia","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1359645424004877","RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
Atomistically informed mesoscale modelling of deformation behavior of bulk metallic glasses
Both atomistic and mesoscale simulation techniques have been extensively employed to gain fundamental understanding of the structures, deformation mechanisms, and structure-property relationships in bulk metallic glasses (BMGs), each with its unique strengths and limitations. Nevertheless, there is a limited degree of synergistic integration between the two approaches. In this study, we extract key properties of shear transformation zones (STZs) directly from the atomistic simulations, including their size, number of shear modes, eigenstrain, and most importantly, the activation energy barrier spectrum as a function of cooling history and strain rate. We then incorporate these STZ properties into a heterogeneously randomized STZ dynamic model implemented in a kinetic Monte Carlo algorithm to study parametrically the deformation microstructure, shear band formation and stress-strain behavior of BMGs. Two important characteristics of STZ activation that dictate the strength and ductility of a glass are identified. One is the average of the activation energy barrier spectrum (approximated by a Gaussian distribution), determined by the glass composition and processing history such as the cooling rate. The other is the amount of shift of the Gaussian distribution towards smaller activation energy barrier values during deformation, which is determined by the initial structural states and strain rate during deformation, and exhibits a saturation value. These findings have allowed us to gain important fundamental insights into the correlation between the degree of shear-induced softening and the general deformation behavior of BMGs, leading to a better understanding of the correlation between the processing history/loading condition and the mechanical behavior.
期刊介绍:
Acta Materialia serves as a platform for publishing full-length, original papers and commissioned overviews that contribute to a profound understanding of the correlation between the processing, structure, and properties of inorganic materials. The journal seeks papers with high impact potential or those that significantly propel the field forward. The scope includes the atomic and molecular arrangements, chemical and electronic structures, and microstructure of materials, focusing on their mechanical or functional behavior across all length scales, including nanostructures.