{"title":"通过挤压速度优化双峰组织,提高纳米tic /AZ61复合材料的塑性和韧性","authors":"","doi":"10.1016/j.jma.2023.02.011","DOIUrl":null,"url":null,"abstract":"<div><div>In this study, the nano-TiC/AZ61 composites with different heterogeneous bimodal grain (HBG) structures and uniform structure are obtained by regulating the extrusion speed. The effect of HBG structure on the mechanical properties of the composites is investigated. The increasing ductility and toughening mechanism of HBG magnesium matrix composites are carefully discussed. When the extrusion speed increases from 0.75 mm/s to 2.5 mm/s or 3.5 mm/s, the microstructure transforms from uniform to HBG structure. Compared with Uniform-0.75 mm/s composite, Heterogeneous-3.5 mm/s composite achieves a 116.7% increase in ductility in the plastic deformation stage and almost no reduction in ultimate tensile strength. This is mainly because the lower plastic deformation inhomogeneity and higher strain hardening due to hetero-deformation induced (HDI) hardening. Moreover, Heterogeneous-3.5 mm/s composite achieves a 108.3% increase in toughness compared with the Uniform-0.75 mm/s composite. It is mainly because coarse grain (CG) bands can capture and blunt cracks, thereby increasing the energy dissipation for crack propagation and improving toughness. In addition, the CG band of the Heterogeneous-3.5 mm/s composite with larger grain size and lower dislocation density is more conducive to obtaining higher strain hardening and superior blunting crack capability. Thus, the increased ductility and toughness of the Heterogeneous-3.5 mm/s composite is more significant than that Heterogeneous-2.5 mm/s composite.</div></div>","PeriodicalId":16214,"journal":{"name":"Journal of Magnesium and Alloys","volume":null,"pages":null},"PeriodicalIF":15.8000,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213956723000592/pdfft?md5=8a0a34e076c7fc11377210d5a72ff323&pid=1-s2.0-S2213956723000592-main.pdf","citationCount":"0","resultStr":"{\"title\":\"Improving the ductility and toughness of nano-TiC/AZ61 composite by optimizing bimodal grain microstructure via extrusion speed\",\"authors\":\"\",\"doi\":\"10.1016/j.jma.2023.02.011\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>In this study, the nano-TiC/AZ61 composites with different heterogeneous bimodal grain (HBG) structures and uniform structure are obtained by regulating the extrusion speed. The effect of HBG structure on the mechanical properties of the composites is investigated. The increasing ductility and toughening mechanism of HBG magnesium matrix composites are carefully discussed. When the extrusion speed increases from 0.75 mm/s to 2.5 mm/s or 3.5 mm/s, the microstructure transforms from uniform to HBG structure. Compared with Uniform-0.75 mm/s composite, Heterogeneous-3.5 mm/s composite achieves a 116.7% increase in ductility in the plastic deformation stage and almost no reduction in ultimate tensile strength. This is mainly because the lower plastic deformation inhomogeneity and higher strain hardening due to hetero-deformation induced (HDI) hardening. Moreover, Heterogeneous-3.5 mm/s composite achieves a 108.3% increase in toughness compared with the Uniform-0.75 mm/s composite. It is mainly because coarse grain (CG) bands can capture and blunt cracks, thereby increasing the energy dissipation for crack propagation and improving toughness. In addition, the CG band of the Heterogeneous-3.5 mm/s composite with larger grain size and lower dislocation density is more conducive to obtaining higher strain hardening and superior blunting crack capability. Thus, the increased ductility and toughness of the Heterogeneous-3.5 mm/s composite is more significant than that Heterogeneous-2.5 mm/s composite.</div></div>\",\"PeriodicalId\":16214,\"journal\":{\"name\":\"Journal of Magnesium and Alloys\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":15.8000,\"publicationDate\":\"2024-08-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.sciencedirect.com/science/article/pii/S2213956723000592/pdfft?md5=8a0a34e076c7fc11377210d5a72ff323&pid=1-s2.0-S2213956723000592-main.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Magnesium and Alloys\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2213956723000592\",\"RegionNum\":1,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"METALLURGY & METALLURGICAL ENGINEERING\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Magnesium and Alloys","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2213956723000592","RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"METALLURGY & METALLURGICAL ENGINEERING","Score":null,"Total":0}
Improving the ductility and toughness of nano-TiC/AZ61 composite by optimizing bimodal grain microstructure via extrusion speed
In this study, the nano-TiC/AZ61 composites with different heterogeneous bimodal grain (HBG) structures and uniform structure are obtained by regulating the extrusion speed. The effect of HBG structure on the mechanical properties of the composites is investigated. The increasing ductility and toughening mechanism of HBG magnesium matrix composites are carefully discussed. When the extrusion speed increases from 0.75 mm/s to 2.5 mm/s or 3.5 mm/s, the microstructure transforms from uniform to HBG structure. Compared with Uniform-0.75 mm/s composite, Heterogeneous-3.5 mm/s composite achieves a 116.7% increase in ductility in the plastic deformation stage and almost no reduction in ultimate tensile strength. This is mainly because the lower plastic deformation inhomogeneity and higher strain hardening due to hetero-deformation induced (HDI) hardening. Moreover, Heterogeneous-3.5 mm/s composite achieves a 108.3% increase in toughness compared with the Uniform-0.75 mm/s composite. It is mainly because coarse grain (CG) bands can capture and blunt cracks, thereby increasing the energy dissipation for crack propagation and improving toughness. In addition, the CG band of the Heterogeneous-3.5 mm/s composite with larger grain size and lower dislocation density is more conducive to obtaining higher strain hardening and superior blunting crack capability. Thus, the increased ductility and toughness of the Heterogeneous-3.5 mm/s composite is more significant than that Heterogeneous-2.5 mm/s composite.
期刊介绍:
The Journal of Magnesium and Alloys serves as a global platform for both theoretical and experimental studies in magnesium science and engineering. It welcomes submissions investigating various scientific and engineering factors impacting the metallurgy, processing, microstructure, properties, and applications of magnesium and alloys. The journal covers all aspects of magnesium and alloy research, including raw materials, alloy casting, extrusion and deformation, corrosion and surface treatment, joining and machining, simulation and modeling, microstructure evolution and mechanical properties, new alloy development, magnesium-based composites, bio-materials and energy materials, applications, and recycling.