共查询到20条相似文献,搜索用时 233 毫秒
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介绍快速凝固镁合金材料研究与开发的物理冶金原理及发展历程。在开发原理中着重介绍快速凝固镁合金的镁基固溶体扩展、新型弥散合金相的形成、晶粒及显微组织细化以及合金钝化等基础理论。在这些研发理论基础上,进一步阐述镁合金雾化快凝、模冷淬火和表面重熔这3种典型的快速凝固制备技术,举例说明了这3种快速凝固技术制备的多种镁合金的各项性能及显微组织特征。综合评价快速凝固技术制备镁合金材料的优势,说明快速凝固技术是开发新型镁合金材料,扩展镁合金在工程材料中应用的重要且具有发展前途的制备技术。 相似文献
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喷射成形是一种先进的快速凝固近终形材料制备技术,在制备高性能钢铁材料方面有着独特的优势和广阔的应用前景.概述喷射成形钢铁材料的工业化生产情况,并对其存在的问题、研究发展方向和应用前景进行了评述. 相似文献
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喷射成形是一种先进的快速凝固近终形材料制备技术,在制备高性能钢铁材料方面有着独特的优势和广阔的应用前景.阐述了各种喷射成形钢铁材料的研究进展,对喷射成形钢铁材料的组织和性能特征进行了综合评述. 相似文献
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喷射成形是一种先进的快速凝固近终形材料制备技术,在制备高性能钢铁材料方面有着独特的优势和广阔的应用前景.介绍了喷射成形技术的基本原理和主要特点,并对喷射成形的发展历程和现状进行了综合评述. 相似文献
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喷射成形是一种先进的快速凝固近终形材料制备技术,在制备高性能钢铁材料方面有着独特的优势和广阔的应用前景.继续介绍喷射成形钢铁材料在特钢等领域的研究进展,并对相应的组织和性能特征进行综合评述. 相似文献
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航空用损伤容限型钛合金研究与应用 总被引:1,自引:0,他引:1
为了满足新型飞机的大尺寸、高减重、长寿命和低成本的设计与应用需求,采用损伤容限型钛合金材料及其应用技术是一条重要途径。国外发达国家已经在新型损伤容限型钛合金材料研制和在先进飞机上的应用方面走在了前列,特别是像中强度的Ti-6Al—4VELI和高强度的Ti一6—22—22S等,已经成功地应用在了美国F-22/F-35,C-17等新一代飞机中,大大地提高了飞机的使用寿命和战斗力。这几年我国先后自主创新发展了中强度损伤容限型钛合金TC4-DT和高强度损伤容限型钛合金TC21,建立了损伤容限型钛合金的口处理加工技术,为我国新型飞机的研制奠定了材料应用技术基础。通过分析国内外损伤容限型钛合金材料及其新型加工工艺技术的研究发展情况,结合我国新型损伤容限型钛合金材料研究进展,重点探讨了新型损伤容限型钛合金的材料特点、性能水平和应用前景。 相似文献
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E. Akman A. Demir T. Canel T. Sınmazçelik 《Journal of Materials Processing Technology》2009,209(8):3705-3713
The high strength to weight ratio and excellent corrosion resistance of titanium alloys allow diverse application in various fields including the medical and aerospace industry. Several techniques have been considered to achieve reliable welds with minimum distortion for the fabrication of components in these industries. Of these techniques, laser welding can provide a significant benefit for the welding of titanium alloys because of its precision and rapid processing capability. For pulse mode Nd:YAG laser welding, pulse shape, energy, duration, repetition rate and peak power are the most important parameters that influence directly or synergistically the quality of pulsed seam welds. In this study, experimental work involved examination of the welding parameters for joining a 3-mm thick titanium alloy using the Lumonics JK760TR Nd:YAG pulsed laser. It has been determined that the ratio between the pulse energy and pulse duration is the most important parameter in defining the penetration depth. Also it has been observed the variation of pulse duration at constant peak power has no influence on the penetration depth. Consequently, to increase the penetration depth during welding, the role of the laser parameters such as pulse energy and duration and peak power have been investigated to join 3 mm thick Ti6Al4V. 相似文献
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Horst E. Friedrich doctoral 《JOM Journal of the Minerals, Metals and Materials Society》1995,47(2):33-35
This article highlights the continued preference for aluminum as a structural material for aircraft, where demands for high performance coupled with the need for weight reduction have led to the use of high-strength aluminum alloys. The ever-increasing demand for a high level of integration of complex structural components calls for the development of appropriate manufacturing processes. As an example, superplastic forming is discussed, combined with innovative bonding techniques such as diffusion bonding and adhesive spot welding. 相似文献
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Linear polarization techniques have been applied to a corrosion system, plain carbon and low-alloy steels in sea water, featured by time-dependent phenomena. Polarization resistance measurements have been interpreted according to equivalent circuits representative of the steel surface behaviour in sea water, in order to avoid misleading contributions arising from the presence of solid corrosion products. Electrochemical data are in good agreement with weight loss measurements throughout four years of immersion in natural sea water and give information about the corrosion mechanisms, mainly based on the settling of localized macro-cathodic and anodic areas. 相似文献
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CVD金刚石自支撑膜的研究进展 总被引:3,自引:3,他引:0
金刚石膜以其最高的硬度、热导率、热震性能以及极高的强度等优点得到了越来越多的关注。自20世纪低压化学气相沉积技术成功制备出金刚石以来,在世界范围内,金刚石的制备技术及应用研究得到了快速发展。分别对国内外自支撑金刚石膜材料的制备技术及相关应用进行简要介绍,并讨论近几年我国在高质量金刚石膜材料制备技术方面取得的进展。目前主要的制备技术有热丝、直流辅助等离子体、直流电弧等离子体喷射、微波等离子体化学气相沉积(CVD)等方法。在小尺寸、高质量金刚石膜的制备技术基础上,21世纪初,国外几大技术强国先后宣布实现了大面积、高质量CVD金刚石膜的制备,并将其用于诸如红外光学窗口等高技术领域。我国也在CVD金刚石膜研发方面不断进步,先后掌握了热丝、直流电弧等离子体喷射、直流辅助等离子体CVD等合成大面积金刚石自支撑膜技术,近几年也掌握了915 MHz微波等离子体CVD技术,这些成果也标志着我国在高质量金刚石膜制备技术领域跟上了世界先进水平。 相似文献
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为了研究7050高强铝合金开坯工艺的变形均匀性及锻件的断裂韧性,采用数值模拟、微观组织分析及紧凑拉伸试样的KIC试验等,分析研究7050高强铝合金铸坯改锻和挤压坯锻造的变形均匀性、显微组织和断裂韧性,得到了两种开坯工艺条件下坯料的平均等效应变、变形均匀系数、晶粒尺寸大小及分布和断裂韧度值。结果表明:铸坯改锻工艺的变形均匀性较好,其平均等效应变约为7.2,变形均匀系数约为0.475;挤压坯锻造工艺的变形均匀性较差,其平均等效应变约为1.9,变形均匀系数约为0.954;铸坯改锻工艺的平均晶粒尺寸与挤压坯锻造工艺基本相当,约为7.5μm,但铸坯改锻工艺的晶粒尺寸比挤压坯锻造更均匀;铸坯改锻工艺下锻件的KIC满足AMS4108F标准要求,而挤压坯锻造工艺不满足,其原因是挤压坯锻造后脆性较大,并残留有挤压织构。 相似文献
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邓克 《锻压装备与制造技术》2007,42(3):43-44
为解决故障率高、控制精度低的缺点,利用插装阀和PLC技术对锻造自动线机械手液压系统进行了改造,设计了插装阀式液压系统,分析了系统工作原理和改造的技术、经济可行性,取得良好的使用效果. 相似文献
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Monitoring of low corrosion rates and localised corrosion in a media with low conductivity is a challenge. In municipal district heating, quality control may be improved by implementing on-line corrosion monitoring if a suitable technique can be identified to measure both uniform and localised corrosion. Electrochemical techniques (LPR, EIS, crevice corrosion current) as well as direct measurement techniques (high-sensitive electrical resistance, weight loss) have been applied in operating plants. Changes in the corrosion processes are best monitored in non-aggressive, low conductivity media with sensitive electrical resistance technique and crevice corrosion current measurements. 相似文献