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Al-Ti、Al-Ti-C中间合金对AZ91D镁合金组织和性能的影响 总被引:1,自引:0,他引:1
研究了Al-5Ti、Al-5Ti-0.25C和Al-8Ti-2C中间合金对AZ91D镁合金的组织、力学性能和耐腐蚀性能的影响。结果表明,添加Al-5Ti中间合金使晶粒粗化,而添加Al-5Ti-0.25C和Al-8Ti-2C中间合金使晶粒细化,Al-8Ti-2C中间舍金的细化效果明显且细化后组织细小均匀;添加Al-5Ti中间合金使合金的力学性能降低,而添加Al-5Ti-0.25C和Al-8Ti-2C中间合金均使合金的拉伸强度和伸长率得到了提高;添加Al-5Ti、Al-5Ti-0.25C和Al-8Ti-2C中间合金均使合金的耐腐蚀性能得到了改善。对于AZ91D合金而言,Al-8Ti-2C中间合金是一种良好的晶粒细化剂。 相似文献
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A series of die casting heat-resistant magnesium alloys based on Mg-Al system were developed for automotive application by adding Y and various amounts of Ca. The mechanical properties and microstructures of die casting AZ91 alloy with combined addition of Y and Ca were investigated by optical microscopy, scanning electronic microscopy, X-ray diffractometry and mechanical property test. The results show that the combined addition of Y and Ca can refine the as-die-cast microstructure, result in the formation of Al2Ca phase and Al2Y phase, and inhibit the precipitation of Mg17Al12 phase. The combined addition of Y and small amount of Ca has little influence on the ambient temperature tensile properties, but increasing the content of Ca can improve significantly the tensile strength at both ambient and elevated temperatures. It is found that for AZ91-1Y-xCa alloy, the hardness and the elevated temperature tensile strength increase, while the elongation decreases with increasing the addition of Ca. The mechanism of mechanical properties improvement caused by the combined addition of Y and Ca was also discussed. 相似文献
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对同一加工工艺得到的挤压态纯镁和AZ80镁合金分别进行6%预压缩,之后对无预压缩和预压缩试样在180 ℃退火20 h,采用光学显微镜、扫描电镜和透射电镜及压缩试验机等对其组织和强度进行了观察和测定,以研究预孪生纯镁及AZ80镁合金退火过程的性能演变及其机制。结果表明:6%预压缩纯镁经180 ℃退火20 h后,屈服强度较未退火试样降低,不存在退火硬化效应。无预压缩AZ80镁合金直接退火处理后,屈服强度与退火处理前几乎不变;而6%预压缩AZ80镁合金经180 ℃退火20 h后,因组织中有较多的白色第二相颗粒在孪晶和孪晶界析出,阻碍位错的运动和孪晶扩展,屈服强度较退火前提高了20 MPa,出现了明显的退火强化效应。 相似文献
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为了研究7075铝合金对AZ91镁合金组织与性能的影响,采用光学显微镜、扫描电镜、X 射线衍射仪、万能材料试验机研究了AZ91镁合金的显微组织与力学性能。结果表明:向AZ91镁合金中加入7075铝合金可使该合金的铸态组织明显细化,当7075铝合金含量超过4%(质量分数,下同)时,AZ91镁合金铸态组织中Mg17Al12相数量明显减少,并且组织中生成了Al6Mn新相。合金抗拉强度与延伸率随着7075铝合金加入量的增加而提高,当7075铝合金的加入达到4%,其抗拉强度与延伸率达到最大值,分别为186 MPa和8.2% 相似文献
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轧制工艺对AZ31B镁合金薄板组织与性能的影响 总被引:2,自引:1,他引:1
研究了轧制温度和轧制速度对AZ31B镁合金薄板微观组织演变和力学性能的影响。结果表明,轧辊加热有利于镁合金薄板成型;AZ31B镁合金在低温或低速轧制时薄板纵向组织为大量的切变带,切变带区域包含大量孪晶组织,横向组织为含极少量孪晶的等轴晶组织;在轧制温度为400℃和轧制速度为16m/min轧制时,由于动态再结晶,横纵截面组织均为等轴晶。AZ31镁合金薄板的最佳轧制制度为轧辊温度为70℃、轧制温度为400℃、轧制速度为6m/min,此工艺轧制的薄板横向抗拉强度、屈服强度和伸长率分别为350MPa、300MPa和12%,纵向为345MPa、290MPa和11.2%,纵向与横向性能差别明显减小。 相似文献
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研究了镁合金AZ91D-0.3%Be-Sr的阻燃性及Sr对合金显微组织和力学性能的影响,结果表明,在镁合金AZ91D中加入0.3%Be。显著提高了阻燃性,使试验合金可在无覆盖和保护的条件下直接暴露在大气中熔炼。加入少量Sr可使镁合金AZ91D-0.3%Be-Sr的组织得到细化,力学性能显著提高。X射线衍射分析表明,阻燃机理是在合金液表面形成致密的MgO-BeO复合保护膜,阻止了镁合金的进一步氧化燃烧。 相似文献
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AZ31镁合金的热挤压变形和力学性能分析 总被引:1,自引:0,他引:1
为了掌握高精度镁合金管材的生产工艺,通过对铸锭的均匀化处理,借助500 t挤压机、拉伸试验机、金相显微镜和透射电镜(TEM)对AZ31镁合金管材的等温挤压过程进行了研究,试制了AZ31镁合金挤压薄壁管材,获得了尺寸精度高、粗糙度小和壁厚差小的管材;分析了不同挤压条件下的AZ31镁合金管材的尺寸精度、组织、力学性能.研究结果表明:在挤压温度为623士20K挤出管材经523K×3h退火时其性能较好,抗拉强度、屈服强度和延伸率分别为270 MPa,175 MPa和23.1%. 相似文献
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The La2(CO3)3 addition makes the grain of AZ91 alloy be refined obviously.The average primary dendrite size of the alloy decreases from 150 to 50 μm.The microstructure of typical dendrite turns into the equal-axed grain with the addition of 2.5 wt.% La2(CO3)3 refiner.The mechanical properties tests indicate that the tensile strength and especially elongation of the alloys are improved with the addition of La2(CO3)3 and their maximum enhancing rates based on the La2(CO3)3-free AZ91 alloy are 26% and 5.2 times at 2.5 wt.% La2(CO3)3 refiner respectively. 相似文献
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Nd对AZ31镁合金微观组织与力学性能的影响 总被引:3,自引:0,他引:3
研究了Nd对AZ31镁合金微观组织和力学性能的影响.结果表明:Nd在AZ31合金中的吸收率达95%,Nd加入AZ31合金中形成了Al2Nd和Mg12Nd金属间化合物,Nd使合金的平均晶粒尺寸减小,力学性能提高.含Nd的AZ31合金铸态抗拉强度、屈服强度和伸长率值分别为245 Mpa、171 Mpa和9%. 相似文献
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挤压速度和电磁铸造锭坯对AZ31镁合金板材组织和性能影响 总被引:1,自引:0,他引:1
文章研究挤压条件下挤压速度和电磁铸造锭坯对挤压态AZ31镁合金板材组织和性能的影响。研究结果发现,挤压速度比较低时,板材晶粒尺寸小,板材的表面质量比较好;随着挤压速度的降低,抗拉强度、屈服强度和延伸率都有一定的提高。由于镁合金是HCP的晶体结构,同时对挤压速度非常敏感,对变形均匀性影响比较大,因此造成挤压板材的内外晶粒大小不均。在电磁场的作用下,溶质在晶内的固溶度增大,同时晶粒大小也比常规铸造的细小,因此电磁铸造的锭坯经挤压机挤压后,挤压板材的晶粒尺寸比较细小,且强度和塑性都有所提高。 相似文献
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Microstructure and mechanical properties of wrought magnesium alloy AZ31B welded by laser-TIG hybrid 总被引:5,自引:0,他引:5
The laser-TIG hybrid welding was mainly used to weld the wrought magnesium alloy AZ31B. The tech-nical characteristics of laser-TIG hybrid welding process was investigated and the interactional mechanism between laser and arc was discussed, at the same time the microstructure and mechanical properties of the wrought magnesi-um alloy AZ31B using laser-TIG hybrid welding were analyzed by optical microscope, EPMA, SEM, tensile ma-chine, hardness machine. The experimental results show that the presence of laser beam boosts up the stability of the arc during high speed welding and augments the penetration of weld; the crystal grains of magnesium alloy weld are fine without porosity and cracks in the best welding criterion and the microstructure of HAZ does not become coarse obviously. The elements profile analysis reveals that Mg content in the weld is lower than that of the base metal, but Al content is higher slightly. Under this experimental condition, the wrought magnesium alloy AZ31B joint can be achieved using laser-TIG hybrid process and the tensile strength of the joint is equivalent to that of the base metal. 相似文献
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TENSILE STRENGTH AND CREEP RESISTANCE OF Mg-9Al-1ZnBASED ALLOYS WITH CALCIUM ADDITION 总被引:11,自引:0,他引:11
Y.S. Sun W.M. Zhang X.G. Mm Department of Materials Science Engineering Southeast University Nanjing China 《金属学报(英文版)》2001,14(5):330-334
1. IntroductionIn the paJst decade cast magnesium alloys have enjoyed a renaissance in many manu-facturing industries, especially the automotive and electronic ind.stri.s[1--4]. However, theuse of magnesium alloys for engineering applications is still restricted to a few structuralparts although they offer lightweight, high stiffness, excellent machinability and the bestalternative fOr weight reduction[4]. The principal technical challenge to the widespreaduse of magnesium castings in structu… 相似文献