{"title":"等角压制后镍的内应力及其来源","authors":"","doi":"10.1134/s1063785023700104","DOIUrl":null,"url":null,"abstract":"<span> <h3>Abstract</h3> <p>The internal structure of grains, as well as the amplitude of internal stresses and their sources, in ultrafine grained technically pure nickel obtained by equal-channel angular pressing deformation was studied by the method of transmission electron microscopy. Under equal-channel angular pressing, the samples have been subjected to shear deformation by compression along two intersecting channels of equal diameter at an angle of 120° and temperature <em>T</em> = 400°C without intermediate annealing. Number of passes <em>n</em> = 4. The equal-channel angular pressing is found to lead to the formation of particles of secondary phases in ultrafine grained nickel with nanometer size and localized inside, at the boundaries and the joints of grains. The sources of internal stresses are revealed and their amplitude is determined. Determination of the amplitude of internal stresses is based on the determination of the curvature–torsion of the crystal lattice along bending extinction contours. It has been established that the sources of internal stresses are grain joints in which particles of secondary phases are present or absent; grain boundaries at which particles of secondary phases are present or absent; particles located on dislocations inside grains, and, finally, the dislocation structure in grains or parts of grains in which there are no particles of secondary phases. It has been found that internal stresses from all sources involve all grains regardless of their internal structure and are predominantly elastic in nature. This means that equal-channel angular pressing led mainly to the elastic distortion of nickel lattice.</p> </span>","PeriodicalId":784,"journal":{"name":"Technical Physics Letters","volume":null,"pages":null},"PeriodicalIF":0.8000,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Internal Stresses and Their Sources in Nickel after Equal-Channel Angular Pressing\",\"authors\":\"\",\"doi\":\"10.1134/s1063785023700104\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<span> <h3>Abstract</h3> <p>The internal structure of grains, as well as the amplitude of internal stresses and their sources, in ultrafine grained technically pure nickel obtained by equal-channel angular pressing deformation was studied by the method of transmission electron microscopy. Under equal-channel angular pressing, the samples have been subjected to shear deformation by compression along two intersecting channels of equal diameter at an angle of 120° and temperature <em>T</em> = 400°C without intermediate annealing. Number of passes <em>n</em> = 4. The equal-channel angular pressing is found to lead to the formation of particles of secondary phases in ultrafine grained nickel with nanometer size and localized inside, at the boundaries and the joints of grains. The sources of internal stresses are revealed and their amplitude is determined. Determination of the amplitude of internal stresses is based on the determination of the curvature–torsion of the crystal lattice along bending extinction contours. It has been established that the sources of internal stresses are grain joints in which particles of secondary phases are present or absent; grain boundaries at which particles of secondary phases are present or absent; particles located on dislocations inside grains, and, finally, the dislocation structure in grains or parts of grains in which there are no particles of secondary phases. It has been found that internal stresses from all sources involve all grains regardless of their internal structure and are predominantly elastic in nature. 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引用次数: 0
摘要
摘要 采用透射电子显微镜方法研究了通过等通道角压变形获得的超细晶粒技术纯镍的晶粒内部结构、内应力振幅及其来源。在等沟道角压下,样品沿两个直径相等的相交沟道以 120° 角和温度 T = 400°C 受压而发生剪切变形,中间不进行退火。压制次数 n = 4。研究发现,等角压制会导致超细晶粒镍中形成纳米级尺寸的次生相颗粒,并集中在晶粒内部、晶粒边界和接合处。揭示了内应力的来源并确定了其振幅。内应力振幅的确定基于沿弯曲消光等值线确定晶格的曲率-扭转。已确定的内应力来源包括:存在或不存在次生相颗粒的晶粒接合处;存在或不存在次生相颗粒的晶粒边界;位于晶粒内部位错上的颗粒,以及晶粒或晶粒部分中不存在次生相颗粒的位错结构。研究发现,无论晶粒的内部结构如何,所有来源的内应力都会涉及所有晶粒,而且主要是弹性内应力。这意味着等通道角压主要导致镍晶格的弹性变形。
Internal Stresses and Their Sources in Nickel after Equal-Channel Angular Pressing
Abstract
The internal structure of grains, as well as the amplitude of internal stresses and their sources, in ultrafine grained technically pure nickel obtained by equal-channel angular pressing deformation was studied by the method of transmission electron microscopy. Under equal-channel angular pressing, the samples have been subjected to shear deformation by compression along two intersecting channels of equal diameter at an angle of 120° and temperature T = 400°C without intermediate annealing. Number of passes n = 4. The equal-channel angular pressing is found to lead to the formation of particles of secondary phases in ultrafine grained nickel with nanometer size and localized inside, at the boundaries and the joints of grains. The sources of internal stresses are revealed and their amplitude is determined. Determination of the amplitude of internal stresses is based on the determination of the curvature–torsion of the crystal lattice along bending extinction contours. It has been established that the sources of internal stresses are grain joints in which particles of secondary phases are present or absent; grain boundaries at which particles of secondary phases are present or absent; particles located on dislocations inside grains, and, finally, the dislocation structure in grains or parts of grains in which there are no particles of secondary phases. It has been found that internal stresses from all sources involve all grains regardless of their internal structure and are predominantly elastic in nature. This means that equal-channel angular pressing led mainly to the elastic distortion of nickel lattice.
期刊介绍:
Technical Physics Letters is a companion journal to Technical Physics and offers rapid publication of developments in theoretical and experimental physics with potential technological applications. Recent emphasis has included many papers on gas lasers and on lasing in semiconductors, as well as many reports on high Tc superconductivity. The excellent coverage of plasma physics seen in the parent journal, Technical Physics, is also present here with quick communication of developments in theoretical and experimental work in all fields with probable technical applications. Topics covered are basic and applied physics; plasma physics; solid state physics; physical electronics; accelerators; microwave electron devices; holography.