{"title":"显微结构表征揭示坎波德尔谢洛陨石碎片冲击变形的证据","authors":"Graeme J. Francolini, Thomas B. Britton","doi":"arxiv-2408.16901","DOIUrl":null,"url":null,"abstract":"The study of meteorites and their microstructures is a topic which spans\nmultiple fields of research, such as meteoritics and materials science. For\nmaterials scientists and engineers, the extreme and unusual conditions which\nthese microstructures form allow for insight into materials which would exist\nat the edge of our thermomechanical processing abilities. One such\nmicrostructure found in low-shock event iron meteorites is Neumann bands. These\nbands are an array of lenticular deformation twins that form throughout the\nFe-Ni matrix with numerous intersections, resulting in many high stress and\nstrain regions within the material's surface. The existence of these regions\nand the shocks that formed them encourage atypical strain accommodating\nmechanisms and structural changes of the material. However, direct\ninvestigation of the deformation twin intersections and the microstructural\nbehaviour in and around these regions has been limited. In this work,\ninvestigation of these regions in a Campo del Cielo meteorite fragment, with\nelectron backscatter diffraction (EBSD) and forescatter electron (FSE) imaging,\nrevealed two primary findings: high-intensity pattern doubling mirrored across\nthe {110} band at twin-twin intersection and microband formation across the\nsample surface, which suggest multilayer twinning and constraint of the crystal\nstructure at points of twin-twin intersection. Microbands were found to form\nalong the {110} plane and in regions near Neumann bands. The simultaneous\nexistence of Neumann bands (microtwins) and microbands is presented here for a\nBCC material, and it is believed the Neumann band and microbands formed during\ndifferent types and/or shock events. The presence of both Neumann bands and\nmicrobands within a BCC iron meteorite is previously unreported and may be\nvaluable in furthering our understanding of shock deformation within iron-based\nmaterials.","PeriodicalId":501270,"journal":{"name":"arXiv - PHYS - Geophysics","volume":"17 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Microstructural characterization to reveal evidence of shock deformation in a Campo del Cielo meteorite fragment\",\"authors\":\"Graeme J. Francolini, Thomas B. Britton\",\"doi\":\"arxiv-2408.16901\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The study of meteorites and their microstructures is a topic which spans\\nmultiple fields of research, such as meteoritics and materials science. For\\nmaterials scientists and engineers, the extreme and unusual conditions which\\nthese microstructures form allow for insight into materials which would exist\\nat the edge of our thermomechanical processing abilities. One such\\nmicrostructure found in low-shock event iron meteorites is Neumann bands. These\\nbands are an array of lenticular deformation twins that form throughout the\\nFe-Ni matrix with numerous intersections, resulting in many high stress and\\nstrain regions within the material's surface. The existence of these regions\\nand the shocks that formed them encourage atypical strain accommodating\\nmechanisms and structural changes of the material. However, direct\\ninvestigation of the deformation twin intersections and the microstructural\\nbehaviour in and around these regions has been limited. In this work,\\ninvestigation of these regions in a Campo del Cielo meteorite fragment, with\\nelectron backscatter diffraction (EBSD) and forescatter electron (FSE) imaging,\\nrevealed two primary findings: high-intensity pattern doubling mirrored across\\nthe {110} band at twin-twin intersection and microband formation across the\\nsample surface, which suggest multilayer twinning and constraint of the crystal\\nstructure at points of twin-twin intersection. Microbands were found to form\\nalong the {110} plane and in regions near Neumann bands. The simultaneous\\nexistence of Neumann bands (microtwins) and microbands is presented here for a\\nBCC material, and it is believed the Neumann band and microbands formed during\\ndifferent types and/or shock events. The presence of both Neumann bands and\\nmicrobands within a BCC iron meteorite is previously unreported and may be\\nvaluable in furthering our understanding of shock deformation within iron-based\\nmaterials.\",\"PeriodicalId\":501270,\"journal\":{\"name\":\"arXiv - PHYS - Geophysics\",\"volume\":\"17 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-08-29\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"arXiv - PHYS - Geophysics\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/arxiv-2408.16901\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv - PHYS - Geophysics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2408.16901","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
摘要
对陨石及其微观结构的研究是一个横跨多个研究领域的课题,如陨石学和材料科学。对于材料科学家和工程师来说,这些微观结构所形成的极端和不寻常的条件可以让他们深入了解那些存在于我们热机械加工能力边缘的材料。在低冲击事件铁陨石中发现的一种此类微结构是诺伊曼带。这些条带是在整个铁-镍基体中形成的透镜状变形孪晶阵列,有许多交叉点,从而在材料表面形成许多高应力和高应变区域。这些区域的存在以及形成这些区域的冲击促进了材料的非典型应变容纳机制和结构变化。然而,对这些区域及其周围的变形孪晶交叉和微观结构行为的直接研究一直很有限。在这项工作中,利用电子反向散射衍射(EBSD)和前散射电子(FSE)成像技术对 Campo del Cielo 陨石碎片中的这些区域进行了研究,发现了两个主要发现:孪晶交汇处{110}波段上的高强度图案加倍镜像和整个样品表面的微带形成,这表明在孪晶交汇点存在多层孪晶和晶体结构约束。微带在{110}平面和诺伊曼带附近区域形成。这里介绍的是同时存在诺伊曼带(微孪晶)和微带的 BCC 材料,认为诺伊曼带和微带是在不同类型和/或冲击事件中形成的。在 BCC 铁陨石中同时存在诺伊曼带和微带是以前从未报道过的,这对于我们进一步了解铁基材料的冲击变形可能是有价值的。
Microstructural characterization to reveal evidence of shock deformation in a Campo del Cielo meteorite fragment
The study of meteorites and their microstructures is a topic which spans
multiple fields of research, such as meteoritics and materials science. For
materials scientists and engineers, the extreme and unusual conditions which
these microstructures form allow for insight into materials which would exist
at the edge of our thermomechanical processing abilities. One such
microstructure found in low-shock event iron meteorites is Neumann bands. These
bands are an array of lenticular deformation twins that form throughout the
Fe-Ni matrix with numerous intersections, resulting in many high stress and
strain regions within the material's surface. The existence of these regions
and the shocks that formed them encourage atypical strain accommodating
mechanisms and structural changes of the material. However, direct
investigation of the deformation twin intersections and the microstructural
behaviour in and around these regions has been limited. In this work,
investigation of these regions in a Campo del Cielo meteorite fragment, with
electron backscatter diffraction (EBSD) and forescatter electron (FSE) imaging,
revealed two primary findings: high-intensity pattern doubling mirrored across
the {110} band at twin-twin intersection and microband formation across the
sample surface, which suggest multilayer twinning and constraint of the crystal
structure at points of twin-twin intersection. Microbands were found to form
along the {110} plane and in regions near Neumann bands. The simultaneous
existence of Neumann bands (microtwins) and microbands is presented here for a
BCC material, and it is believed the Neumann band and microbands formed during
different types and/or shock events. The presence of both Neumann bands and
microbands within a BCC iron meteorite is previously unreported and may be
valuable in furthering our understanding of shock deformation within iron-based
materials.