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为了改善镁合金在熔铸及加工过程中抗氧化燃烧性能,用合金化阻燃方法在Mg-4Zn合金中添加适宜的Y元素制备了阻燃效果优异的Mg-4Zn-3Y合金.采用俄歇电子能谱仪、X射线衍射仪和扫描电镜(SEM+EDS)研究了氧化膜的显微形貌、合金元素分布及其物相组成.结果表明,Mg-4Zn-3Y合金在高温下暴露于大气中时,燃点提高250℃,合金表面生成一层以Y2O3为主的氧化膜,改善镁合金氧化膜的粘附性,提高高温抗氧化和燃烧能力.基于高温氧化热力学分析,建立了Mg-4Zn-3Y合金在高温下的氧化物理模型.Mg-4Zn-3Y合金能在1065K时于大气中保温30min而不燃烧,实现了低Y元素含量镁合金在大气条件下的无保护熔炼. 相似文献
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压铸镁合金的研究进展及发展趋势EI北大核心CSCD 总被引:1,自引:0,他引:1
本文对镁合金现有的各种压铸技术、添加元素提高镁合金蠕变性能、耐蚀性能和镁合金熔炼新技术等方面的研究进展进行了综述;分析了压铸技术、添加合金元素以及对熔体进行净化和气体保护对压铸镁合金抗高温蠕变和耐腐蚀性能的作用;最后,指出了今后压铸镁合金的发展方向。 相似文献
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利用失重法研究不同Gd含量的AZ31镁合金在3.5%(质量分数,下同)Na2SO4溶液中的腐蚀行为,并采用OM,SEM和XRD等检测手段分析稀土Gd对AZ31镁合金微观组织、腐蚀速率和腐蚀形貌等的影响。结果表明:稀土Gd的添加能明显改善AZ31镁合金的耐蚀性能,且当Gd的添加量小于4.12%时,合金的耐蚀性能会随着Gd含量的增加而提高,但继续增大Gd含量时合金的耐蚀性能反而会出现一定程度的下降,其原因是合金中添加过多的Gd后,加剧了基体相与析出相之间的微电偶腐蚀,致使合金的耐蚀性能有所下降。故当Gd的添加量为4.12%时,AZ31镁合金的耐蚀性能最佳。 相似文献
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为提高高强镁合金的力学性能,在Mg-3Gd-2Zn-0.5Zr镁合金中添加了1.5%纳米Ti,对制备出的铸态镁合金试样进行了OM、SEM、XRD分析,并进行了力学性能、阻尼性能和耐磨损性能的测试与分析。结果表明,纳米金属钛的添加,显著提高了合金的力学性能、阻尼性能和耐磨损性能,使合金在6×10-5,20×10-5,40×10-5应变振幅下的阻尼性能分别提高54%,77%和81%;250℃磨损体积和摩擦因数分别减小68%,11%。借此为高强镁合金的纳米改性研究提供进一步指导与借鉴。 相似文献
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The purpose of this paper is to provide a succinct but nevertheless complete mechanistic overview of the various types of magnesium corrosion. The understanding of the corrosion processes of magnesium alloys builds upon our understanding of the corrosion of pure magnesium. This provides an understanding of the types of corrosion exhibited by magnesium alloys, and also of the environmental factors of most importance. This deep understanding is required as a foundation if we are to produce magnesium alloys much more resistant to corrosion than the present alloys. Much has already been achieved, but there is vast scope for improvement. This present analysis can provide a foundation and a theoretical framework for further, much needed research. There is still vast scope both for better fundamental understanding of corrosion processes, engineering usage of magnesium, and also on the corrosion protection of magnesium alloys in service. 相似文献
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Potential Magnesium Alloys for High Temperature Die Cast Automotive Applications: A Review 总被引:3,自引:0,他引:3
Henry Hu Alfred Yu Naiyi Li John E. Allison 《Materials and Manufacturing Processes》2003,18(5):687-717
Magnesium, as a lightweight construction material, has rapidly grown its applications in the automotive industry since the early 1990s. To maximize the weight reduction of vehicles by lightweight magnesium alloys in the coming years, the use of newly developed high-temperature magnesium alloys is expected to increase significantly, particularly in the powertrain applications where the creep resistance is always required. This article reviews recent developments of the creep-resistant magnesium alloys. Fundamental aspects of the creep deformation theory and mechanisms are described. The metallurgical principles for designing the creep-resistant alloys are highlighted. The creep behavior of magnesium and its conventional alloys is discussed based on some microstructure analyses. The mechanical properties, microstructure, and manufacturability of the newly developed creep-resistant magnesium alloys are also overviewed. The further research and development work is outlined in terms of developing magnesium alloys for some potential and value-added automotive applications. 相似文献
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Magnesium based degradable biomaterials: A review 总被引:1,自引:0,他引:1
Magnesium has been suggested as a revolutionary biodegradable metal for biomedical applications. The corrosion of magnesium, however, is too rapid to match the rates of tissue healing and, additionally, exhibits the localized corrosion mechanism. Thus it is necessary to control the corrosion behaviors of magnesium for their practical use. This paper comprehensively reviews the research progress on the development of representative magnesium based alloys, including Mg-Ca, Mg-Sr, Mg-Zn and Mg-REE alloy systems as well as the bulk metallic glass. The influence of alloying element on their microstructures, mechanical properties and corrosion behaviors is summarized. The mechanical and corrosion properties of wrought magnesium alloys are also discussed in comparison with those of cast alloys. Furthermore, this review also covers research carried out in the field of the degradable coatings on magnesium alloys for biomedical applications. Calcium phosphate and biodegradable polymer coatings are discussed based on different preparation techniques used. We also compare the effect of different coatings on the corrosion behaviors of magnesium alloys substrate. 相似文献
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本文总结了稀土镁合金的研究工作。概要论述了稀土镁合金的发展进程;在稀土元素对镁合金性能影响方面,阐明了稀土元素对镁合金密度、电阻系数和导热系数、热膨胀系数、阻尼容量、晶格常数、弹性模量等物理性能以及对拉伸和蠕变等力学性能的影响。在稀土镁合金微观结构研究方面,总结了稀土相的结构,以及稀土相对合金的强化作用,并提出了我们的一些研究结果。 相似文献
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Magnesium alloys show a high specific strength and are therefore increasingly used for light‐weight constructions in transportation industry.[1,2] To predict the behaviour of the material under the influence of cyclic loading it is vital to understand the fatigue behaviour of magnesium alloys. Only when understood properly, it is possible to fully apply the potential weight reduction by using magnesium alloys. A very important aspect in fatigue of magnesium alloys is the influence of a corrosive media and elevated temperatures, of which both are relevant in automotive applications. These two factors tend to have deleterious effects on magnesium alloys and therefore also have to be considered in investigations on the fatigue behaviour of magnesium alloys. 相似文献
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超高强韧镁合金的研发对推广镁合金在高技术领域的应用具有重要意义。镁与稀土均是我国的优势资源,因此在我国发展超高强韧稀土镁合金具有得天独厚的优势,其中Mg-Gd-Y-Zn-Zr系变形镁合金因其接近高强铝合金的超高强度和塑性,近年来受到研究者的广泛关注。综述了超高强韧Mg-Gd-Y-Zn-Zr系变形镁合金的合金成分、常规塑性变形工艺、新型剧烈塑性变形工艺和热处理工艺对该合金显微组织和力学性能的影响规律,以及该超高强韧变形镁合金的显微组织特征和强韧化机理。T5峰时效态超高强韧Mg-8.2Gd-3.8Y-1Zn-0.4Zr(质量分数)挤压合金具有双峰分布的晶粒尺寸“软-硬”复合层片微结构,以及由高密度的基面γ′纳米片状析出相和棱柱面β′纳米析出相形成的近连续网状结构,该挤压合金室温拉伸屈服强度、拉伸强度和断裂延伸率分别为466 MPa、514 MPa和14.5%。介绍了哈尔滨工业大学等单位在超高强韧Mg-Gd-Y-Zn-Zr系变形镁合金的规模化制备和应用方面的研究进展,并展望了Mg-Gd-Y-Zn-Zr系变形镁合金的发展趋势。 相似文献
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高能束技术在镁合金表面改性中的应用 总被引:1,自引:0,他引:1
针对如何提高镁合金强度、硬度、耐磨性、耐腐蚀性等综合性能这一热点问题,系统地介绍了激光束、电子束、离子束3种高能束表面改性技术的原理、方法以及在镁合金表面改性中的应用进展,总结了各工艺方法的优缺点,展望了高能束技术在镁合金表面改性中的发展前景。 相似文献