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累积叠轧工艺对AZ31镁合金板材组织和性能的影响 总被引:1,自引:0,他引:1
采用累积叠轧工艺对AZ31 镁合金薄板进行剧塑性变形,研究了累积叠轧变形过程中镁合金板材的组织及性能演变.实验结果表明,累积叠轧可以有效细化AZ31镁合金板材的晶粒组织,显著改善室温延伸率,是制备大尺寸、高性能细晶镁合金板材的一种有效、经济而且可以实现工业化生产的技术.累积叠轧5道次后AZ31镁合金板材组织均匀,晶粒尺寸为1~2μm左右,晶粒细化源于大的累积变形及表面剪切变形;室温抗拉强度和延伸率可达到349MPa和22.46%,可归因于晶粒细化对镁合金强度和塑性的改善.累积叠轧板材的道次间的加热使ARB组织粗化,减小了累积叠轧过程中晶粒持续细化的效果. 相似文献
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累积叠轧焊(ARB)工艺可以制备超细晶、高性能、大尺寸的金属及合金板材,具有自身突出的优越性,容易实现工业化生产,是目前剧塑性变形工艺领域的研究热点之一。ARB变形金属层间的界面焊合强度是影响其工艺及材料工业应用的主要因素之一。本文对累积叠轧焊工艺的界面焊合特点进行了综述,对道次变形量、ARB变形前后退火工艺、板材表面处理等因素对ARB板材界面焊合性能的影响进行深入分析。同时简要介绍了板材界面焊合质量的表征方法。 相似文献
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通过不同的加工工艺制备具有不同晶粒尺寸和织构的AZ31镁合金板材,通过室温埃里克森试验研究了工艺因素对提高镁合金板材室温成形性能的影响。结果表明:增大晶粒尺寸,减弱基面织构,可以改善镁合金轧板在变形过程中产生的在轧制方向的硬取向,增大镁合金轧板的延伸率,从而提高镁合金室温成形性能;用异步轧制工艺(轧制和退火温度为400℃、异速比为1.5)制备的试样晶粒尺寸增大到20μm、(0002)极图最大极密度仅为2,室温杯突实验测得IE值达到了5.71,显著提高了材料室温成形性能。 相似文献
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目的研究叠轧温度对AZ31镁合金板材组织与性能的影响。方法在450℃和550℃下,对AZ31镁合金板材进行2道次叠轧,研究不同温度下板材界面裂纹的金相组织、RD-ND面晶体取向、力学性能以及断面形貌的异同。结果 450℃累积叠轧制备的ARB2镁合金板材室温断裂伸长率为2.3%,550℃累积叠轧制备的ARB2镁合金板材室温断裂伸长率为8%;450℃叠轧板材中动态再结晶晶粒大多数尺寸约为1~3μm左右,550℃叠轧板材中动态再结晶晶粒大多数尺寸约为600 nm~2μm。结论通过提高温度,可改善界面结合性能,促进基面晶粒往非基面取向偏转,提升了叠轧板材的力学性能,使叠轧板材由较低温度下的脆性断裂向韧性断裂转变。 相似文献
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包铝镁板轧制复合机理的研究 总被引:2,自引:0,他引:2
镁合金由于具有比强度高、比刚度高、电磁屏蔽性能强等特点,而成为当今研究的热点金属材料之一。但是加工变形能力差和不耐腐蚀的缺点限制了镁合金的发展。本文采用轧制复合的方法制备包铝镁板,提高镁合金的加工变形能力和耐腐蚀能力,并研究镁.铝复合机理、工艺制度对镁一铝结合的影响。研究结果表明:镁埠;轧制复合的机制主要是裂口机制,当轧制变形率超过临界值时,才能实现镁-铝良好的结合;轧后退火对镁-铝的结合强度影响很大,退火中镁—铝原子的互扩散有助于提高镁—铝的结合强度,但是中间相的出现大大降低结合强度。 相似文献
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目的通过高温累积叠轧工艺制备出高强度的镁合金,并研究该过程中循环道次对AZ31镁合金板材的微观组织与性能的具体影响。方法对累积叠轧1~5次板材进行微观组织观察,并进行显微硬度的测试,得到不同板材的硬度值,通过X射线衍射分析得到不同板材的取向结果,最终进行力学性能实验,并对比分析。结果随着循环道次的增加,板材抗拉强度有明显改变。从260 MPa先增加至310 MPa,最后稳定在350 MPa左右;非基面织构比重增加;断裂伸长率先降低后升高并稳定在10%左右。结论累积叠轧工艺使得AZ31镁合金板材产生了加工硬化,并显著细化了晶粒。循环道次的增加、孪晶产生和晶界数量显著增多导致强度进一步提高。 相似文献
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The present study was carried out to evaluate the microstructures and mechanical properties of severely deformed Ni-30Cr alloys. Cross-roll rolling (CRR) was introduced as a severe plastic deformation (SPD) process. Ni-30Cr alloy sheets were cold rolled to 90% thickness reduction and subsequently annealed at 700 °C for 30 min to obtain the recrystallized microstructure. Electron back-scattered diffraction (EBSD) was introduced to analyze grain boundary character distributions (GBCDs). The application of CRR to the Ni-30Cr alloy effectively enhanced grain refinement through heat treatment; consequently, the average grain size was significantly refined from 33 μm in the initial material to 0.6 μm. This grain refinement directly improved the mechanical properties, in which yield and tensile strengths significantly increased relative to those of the initial material. We systematically discuss the grain refinement and accompanying improvement in mechanical properties in terms of the effective strain imposed by CRR relative to conventional rolling (CR). 相似文献
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随着镁合金产业的快速发展,如何通过塑性成形方法提高镁合金的耐蚀性成为了重要课题。镁及其合金因具有低密度、高比强度和较好的回收性等优点而受到广泛关注,然而室温变形能力和耐腐蚀性能差等缺点是其广泛应用的瓶颈。在总结镁合金腐蚀特点及面临问题的基础上,综合分析了国内外塑性成形方法对镁合金腐蚀领域的相关研究,综述了不同加工成形方法在提高镁合金耐蚀性应用方面的进展,从腐蚀机理和工艺参数2个方面进行了讨论。介绍了不同塑性成形方法对镁合金耐蚀性的影响机制,其中包括挤压–ECAP、超声滚压处理、等通道转角挤压、热轧处理、触变成形、板材挤压、板材轧制、交叉轧制、异步轧制和异步交叉轧制、压铸、快速凝固、搅拌摩擦焊、增材制造、喷丸等。从成分分布、析出相等微观角度阐述了影响镁合金腐蚀行为的机制,指出了塑性成形方法在提高镁合金耐蚀行为方面存在的问题,为提高镁合金的耐蚀性提出建议。 相似文献
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针对不同方法制备的AZ31镁合金薄板,利用热拉伸试验机和金相显微镜对其在不同温度和变形速率下的流变应力进行了实验研究.结果表明:挤压、交叉、热轧和冷轧等方法制备的AZ31镁合金薄板的应力-应变曲线基本特征是相同的.峰值流变应力随变形温度的升高和应变速率的降低而降低,在低温时具有明显的厚度效应;当温度大于350℃时峰值流变应力几乎不随板材厚度变化而变化;应变速率小于1.0×10-2s-1,变形温度大于150℃下所有AZ31薄板的延伸率均δ≥45%;单向轧制薄板的各向异性随温度提高减小. 相似文献
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U. Draugelates A. Schram C.‐C. Kedenburg 《Materialwissenschaft und Werkstofftechnik》2000,31(5):370-375
Production and characteristics of a SiC‐particle reinforced AM20 magnesium alloy In despite of the increasing interest of the industry in extremely lightweight materials during the last years an intensive industrial use of those materials due to the their restricted cold‐workability caused by the hexagonal lattice is still very limited. The application of magnesium alloys is still a problem due to thier low modulus of elasticity, low creep strength, as well as low hardness and wear‐resisting qualities. To improve the mechanical properties and the modulus of elasticity particle reinforcement showing quasi‐isotropic characteristics turned out to be an outstanding solution possibility for an economical optimization of the characteristics of magnesium alloys. In this contribution the production process of an MMC magnesium alloy charging SiC particles directly into the magnesium melt with simultaneous stirring action is described. In addition to the procedure to select optimal stirring parameters a comparison of the improved characteristics of a particle reinforced AM20 magnesium alloy as cast and as extruded with the unmodified AM20 alloy will be carried out. With regard to an improved forgeability, a forged chain wheel consisting of particle reinforced AM20 magnesium alloy is shown. 相似文献
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Magnesium – future material for automotive industry? Magnesium alloys show a very high potential in automotive applications as constructive metal, whereas the main focus lies on die cast parts. Electronic industry is the major commercial consumer for die castings besides the automobile industry. Room temperature applications like steering wheels and frame components in cars as well as mobile phone‐ or notebook housings are well established. These castings are produced with AZ‐ or AM‐magnesium alloys, which show good room temperature properties and a good castability. The great alloy development challenge in extending the use of magnesium cast alloys are application for higher temperatures. The application in powertrain components is considered to be the benchmark here. Besides alloy development there are also further research activities in development of casting processes. Semi‐solid processes like New‐Rheocasting (NRC), Thoxomolding ? or Thixocasting (TC) are adapted to the requirements of newly developed alloys. Not only cast alloys but also magnesium wrought alloys have moved to the centre of interest in the last decade. Alloy development for improving the formability on the one hand as well as process development in extrusion or rolling has to be done in order to find optimum parameters for deforming magnesium alloys properly. 相似文献
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镁合金作为最轻的金属结构材料,在汽车制造、生物医疗等领域具有极大的应用潜力。激光选区熔化成形镁合金具有高效的制备性能、良好的成分均匀性、优异的力学性能和耐腐蚀性能,因此激光选区熔化成为一种重要的镁合金制备和改性方法。对近几年激光选区熔化镁合金的研究进展进行了综述,从激光工艺参数(激光类型、体能量密度、激光功率、扫描速度、扫描模式、层厚、扫描间距、气氛控制与进粉速度)和粉体状态(粉末形状、粒径分布、粉末对激光束能量吸收率、粉末化学成分)2个方面讨论了该工艺的关键技术;按照纯镁、非稀土镁合金体系、稀土镁合金体系的分类,对激光选区熔化成形镁及镁合金的致密度与微观结构、力学性能与耐腐蚀性能进行了总结;分析了工艺参数与合金成分两方面对该工艺成形镁合金缺陷的影响。为减少激光选区熔化成形镁合金缺陷、均匀化晶粒、溶解硬脆二次相或析出强化相进而改善合金的结构与性能,许多研究对激光选区熔化成形镁合金进行了热等静压、固溶热处理和时效热处理,总结了上述处理方式对AZ体系、WE体系与Mg-Gd体系镁合金的改善效果。最后展望了激光选区熔化成形镁及镁合金在各领域的应用前景与未来可以进行研究的方向。 相似文献