{"title":"高压扭转过程中Mo-Re合金组织演变","authors":"Ivan A. Ditenberg","doi":"10.1016/j.matchar.2025.115538","DOIUrl":null,"url":null,"abstract":"<div><div>The features of the microstructure evolution of Mo-47 %Re alloys under severe plastic deformation by high-pressure torsion were studied. Using the dark-field analysis of discrete and continuous misorientations, depending on the plastic deformation degree, a quantitative certification of the parameters of highly defective structural states was carried out. The main mechanisms of formation of ultrafine-grained and nanocrystalline structural states were revealed. By measuring at different distances from the torsion axis in sections perpendicular to the anvil plane, the microhardness values of the studied alloys were determined, the maximum values of which reach more than 12 GPa. It was established that a decrease in microhardness in the peripheral part at maximum realized deformation values is associated with the formation of cracks along grain boundaries. An analysis of the microstructure transformation features of the studied alloys in a “high-strength state” formed during high-pressure torsion was carried out. It is assumed that under these conditions the dislocation-disclination mechanism and the mechanism of lattice reorientation by quasi-viscous flows of nonequilibrium point defects are the main mechanisms of structural transformation of Mo-47 %Re alloys at the submicrocrystalline and nanoscale levels, respectively.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"229 ","pages":"Article 115538"},"PeriodicalIF":5.5000,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Mo-Re alloys microstructure evolution during high-pressure torsion\",\"authors\":\"Ivan A. Ditenberg\",\"doi\":\"10.1016/j.matchar.2025.115538\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>The features of the microstructure evolution of Mo-47 %Re alloys under severe plastic deformation by high-pressure torsion were studied. Using the dark-field analysis of discrete and continuous misorientations, depending on the plastic deformation degree, a quantitative certification of the parameters of highly defective structural states was carried out. The main mechanisms of formation of ultrafine-grained and nanocrystalline structural states were revealed. By measuring at different distances from the torsion axis in sections perpendicular to the anvil plane, the microhardness values of the studied alloys were determined, the maximum values of which reach more than 12 GPa. It was established that a decrease in microhardness in the peripheral part at maximum realized deformation values is associated with the formation of cracks along grain boundaries. An analysis of the microstructure transformation features of the studied alloys in a “high-strength state” formed during high-pressure torsion was carried out. It is assumed that under these conditions the dislocation-disclination mechanism and the mechanism of lattice reorientation by quasi-viscous flows of nonequilibrium point defects are the main mechanisms of structural transformation of Mo-47 %Re alloys at the submicrocrystalline and nanoscale levels, respectively.</div></div>\",\"PeriodicalId\":18727,\"journal\":{\"name\":\"Materials Characterization\",\"volume\":\"229 \",\"pages\":\"Article 115538\"},\"PeriodicalIF\":5.5000,\"publicationDate\":\"2025-09-04\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Materials Characterization\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S1044580325008277\",\"RegionNum\":2,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MATERIALS SCIENCE, CHARACTERIZATION & TESTING\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Materials Characterization","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1044580325008277","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, CHARACTERIZATION & TESTING","Score":null,"Total":0}
Mo-Re alloys microstructure evolution during high-pressure torsion
The features of the microstructure evolution of Mo-47 %Re alloys under severe plastic deformation by high-pressure torsion were studied. Using the dark-field analysis of discrete and continuous misorientations, depending on the plastic deformation degree, a quantitative certification of the parameters of highly defective structural states was carried out. The main mechanisms of formation of ultrafine-grained and nanocrystalline structural states were revealed. By measuring at different distances from the torsion axis in sections perpendicular to the anvil plane, the microhardness values of the studied alloys were determined, the maximum values of which reach more than 12 GPa. It was established that a decrease in microhardness in the peripheral part at maximum realized deformation values is associated with the formation of cracks along grain boundaries. An analysis of the microstructure transformation features of the studied alloys in a “high-strength state” formed during high-pressure torsion was carried out. It is assumed that under these conditions the dislocation-disclination mechanism and the mechanism of lattice reorientation by quasi-viscous flows of nonequilibrium point defects are the main mechanisms of structural transformation of Mo-47 %Re alloys at the submicrocrystalline and nanoscale levels, respectively.
期刊介绍:
Materials Characterization features original articles and state-of-the-art reviews on theoretical and practical aspects of the structure and behaviour of materials.
The Journal focuses on all characterization techniques, including all forms of microscopy (light, electron, acoustic, etc.,) and analysis (especially microanalysis and surface analytical techniques). Developments in both this wide range of techniques and their application to the quantification of the microstructure of materials are essential facets of the Journal.
The Journal provides the Materials Scientist/Engineer with up-to-date information on many types of materials with an underlying theme of explaining the behavior of materials using novel approaches. Materials covered by the journal include:
Metals & Alloys
Ceramics
Nanomaterials
Biomedical materials
Optical materials
Composites
Natural Materials.