现代铝锂合金的疲劳与断裂特性

综述了不同类型的现代铝锂合金疲劳与断裂特性，从工程应用角度，针对铝锂合金板材疲劳寿命，长、短裂纹扩展速率和环境的作用，断裂韧性及其低温行为等方面进行了论述和评价，与同类型的普通铝合金进行了对比，分析了现代铝锂合金应用于航空航天工业的有利条件及在疲劳与断裂性能方面尚存在的问题，并对铝锂合金的研究与发展提出了一些看法。     

俄罗斯的铝锂合金工业

综合评述了俄罗斯在铝锂合金开发、生产与应用领域的发展与现状.并着重介绍了俄罗斯在铝锂合金生产技术发展中所取得的一些重要成就.最后,对俄罗斯铝锂合金工业技术的一些成功经验进行了简要总结.     

世界铝-锂合金工业概要及中国与它们的差距

对世界铝-锂合金工业的发展历程做了简要的回顾,对其现状作了较详细的全面的阐述。美国、俄罗斯、法国是当今铝-锂合金研究、生产、应用大国与强国,中国在铝-锂合金研发与材料生产方面与发达国家还有一定的差距。2015年全世界Al-Li合金材料的生产能力约35kt/a,而中国的生产能力还不到3kt/a,同时还有一些短板需要补齐。     

基于专利分析的中国铝锂合金创新态势研究

铝锂合金因具有低密度、高弹性模量、高比强度及高比刚度等优点已成为当前各国争相发展的重要航空材料。本文从总体趋势、专利分类、主要申请人和技术特点等方面对中国铝锂合金专利情况进行了分析,并提出了相关建议。越来越多的企业和研究机构开始关注铝锂合金相关领域的研究,我国已基本形成相对完善的铝锂合金专利体系,但我国企业铝锂合金专利布局与国外企业相比尚存在一定差距。     

航空航天用铝锂合金研究进展及发展趋势

航空航天用Al-Li合金因具有突出的低密度、优异的综合性能和广阔的应用前景,已逐步成为与2×××、7×××系合金并列的新一代高性能铝合金.概述了近百年来国内外铝锂合金的研发历史和工业应用情况,分析了第一代至第三代铝锂合金的研发和性能改进思路,同时也总结了我国铝锂合金产业化大规模应用需要进一步克服的技术难点.最后针对未来...     

2195铝锂合金热处理制度工艺研究

随着航空航天工业的发展,对于低密度、高强度的铝合金材料需求越来越多,铝锂合金势必是一种发展趋势。近期,公司开展了2195铝锂合金试验研究,本文通过正交试验研究确定了最佳的热处理工艺,最终确定了2195铝锂合金挤压材的最优热处理制度。     

2050铝锂合金热变形行为研究

利用热模拟压缩试验研究了变形温度300～540℃、应变速率0.01～10/s时2050铝锂合金的热变形行为,并通过光学显微镜(OM)、扫描电镜(SEM)和电子背散射衍射技术(EBSD)分析了合金热压缩态和固溶淬火态的组织演变规律.研究结果表明:2050铝锂合金流变应力随变形温度的升高而降低,随应变速率的提高而增大.合金...     

世界锂业新产品Li

介绍了世界锂工业的发展近况，以及锂离子电池、锂陶瓷、铝锂合金、锂复合材料、锂医药和锂橡胶等新产品。     

熔剂在铝锂合金中的行为

介绍了铝锂合金的氧化特点,并详细分析研究熔剂在铝锂合金熔炼,铸造过程中的保护,精炼行为,认为熔剂保护比氩气保护更容易得到合格氢含量的铸锭,尤其是结晶器中使用熔剂保护时所特有的除氢作用和熔剂自滑作用,使铸锭含量显著降低,表面质量大幅度提高,从而减少或避免铸锭的裂纹倾向。     

铝锂合金的搅拌摩擦焊接技术研究与应用现状

对铝锂合金搅拌摩擦焊的焊接区宏观形貌、析出相等微观组织和拉伸、疲劳等力学性能进行了综述和分析,介绍了铝锂合金搅拌摩擦焊接在航空航天领域的最新应用,提出了下一步铝锂合金搅拌摩擦焊的发展方向。     

稀土镁合金的研究进展

从防氧化、除氢、合金流动性、细化品粒与强化作用等方面概括稀土元素在镁合金中的作用，综述稀土镁中间合金，铸造、变形稀土镁合金与快速凝固稀土镁合金的最新研究动向与成果，并简介发展非品镁合金与镁合金的超塑性研究的巨大潜力。     

稀土在新材料应用研究中的新进展

介绍了稀土永磁材料、稀土贮氢材料以及稀土对钛及钛合金、铝锂合金性能影响方面的研究最新进展，并就今后稀土在新材料领域的应用提出了几点看法。     

Development and Processing of Novel Aluminum Powder Metallurgy Materials for Heat Sink Applications

The objective of this research was to design aluminum powder metallurgy (PM) alloys and processing strategies that yielded sintered products with thermal properties that rivaled those of the cast and wrought aluminum alloys traditionally employed in heat sink manufacturing. Research has emphasized PM alloys within the Al-Mg-Sn system. In one sub-theme of research, the general processing response of each PM alloy was investigated through a combination of sintering trials, sintered density measurements, and microstructural assessments. In the second, the thermal properties of sintered products were studied in detail. Thermal conductivity was first determined using a calculated approach through discrete measurements of specific heat capacity, thermal diffusivity, and density and subsequently verified using a transient plane source technique on larger specimens. Experimental PM alloys achieved >99 pct theoretical density and exhibited thermal conductivity that ranged from 179 to 225 W/m K. Thermal performance was largely dominated by the amount of magnesium present within the aluminum grains and, in turn, bulk alloy chemistry. Data confirmed that the novel PM alloys were highly competitive with even the most advanced heat sink materials such as wrought 6063 and 6061.     

低成本高性能钛合金研究进展

基于钛合金材料在新一代航空航天飞行器上大量使用,以满足减重、延长寿命的设计和使用要求,因此钛合金低成本化以及钛合金材料成形的低成本化已成为国内外钛工业领域研究的重要方向。发展具有我国自主知识产权的航空用高性能低成本钛合金材料及其加工技术,是提高我国钛合金材料在航空领域用量和应用水平的重要途径。介绍了国内外主要钛合金生产国一些低成本钛合金的研发背景、典型力学性能以及实际应用情况,指出了降低航空用高性能钛合金材料的发展思路。     

耐热铝合金的研究及应用现状与展望

文章综述了航空航天、高压输电、核乏燃料贮存、石油钻探等主要领域用耐热铝合金的性能特点、开发及应用现状,对耐热铝合金应用前景进行了展望,并提出了我国耐热铝合金研发和产业化发展建议.     

Formation of Nondendritic Primary Aluminum Phase in Hypoeutectic Alloys in Controlled Diffusion Solidification (CDS): A Hypothesis

Controlled diffusion solidification (CDS) is a novel process wherein specific Al alloys can be cast by mixing two precursor alloys of specific compositions and temperature and subsequently casting the resultant mixture. This process enables a nondendritic morphology of the primary Al phase in the cast samples, which is beneficial in mitigating hot tearing tendencies and enabling castability of dilute Al (wrought) alloys to obtain castings with superior mechanical and performance properties. In this study, a hypothesis is proposed to describe the mechanism of the CDS process, specifically the processes of mixing two precursor alloys and a subsequent solidification process. Al – 4.5 wt pct Cu was used as an example alloy system to propose a hypothesis and to verify the various features in the mechanism of mixing two alloys. Experimental results show that the mixing process naturally causes copious nucleation of one of the alloys mixed and that the turbulence energy during mixing distributes these nuclei uniformly to enable a favorable solidification condition for a nondendritic cast microstructure. It is critical that the alloy with the higher thermal mass (mass and temperature) is mixed into the alloy with lower thermal mass to obtain a valid CDS process and that the reverse will not yield a favorable homogeneous cast sample. Certain critical parameters during the CDS process have also been identified and quantified for a favorable microstructure of the casting.     

欧盟对航空航天器变形镁合金应用的评估

回顾了变形镁合金的生产与在航空器方面的应用。2005年～2008年欧盟在PF6框架内进行了一个名为"AEROMAG"的研究计划,对现行变形镁合金的加工性能、成形工艺、表面处理、燃烧性能、连接工艺与结构性能等作了精心的评价,没有一个镁合金的各项性能可全面与5083及2024-T3铝合金的相抗衡,镁合金现在还没有取代航空铝合金的可能性。     

粉末注射成形钛合金粘结剂体系的研究进展

钛及钛合金具有低比重、高比强度、优异的生物相容性以及良好的耐腐蚀性等特点,在航空航天、生物医疗、化工、船舶、汽车等领域极具应用潜力。钛合金粉末注射成形技术（powder injection molding,PIM）提高了材料的利用率,实现了中小型复杂形状钛产品的大批量、低成本制备,显著地推动了钛及钛合金产品的生产及应用。目前关于粉末注射成形钛合金粘结剂体系的相关文献报道十分有限,新型粉末注射成形钛合金粘结剂体系的开发处于停滞不前的状态。本文分析总结了不同粉末注射成形钛合金粘结剂体系的研究现状,并针对目前存在的问题提出改进措施。     

The effects of molybdenum and aluminum on the thermal expansion coefficients of nickel-base alloys

The effects of molybdenum and aluminum on the mean linear thermal expansion coefficients from room temperature to 1050°C were determined for two types of nickel-base alloys. The Solid Solution Alloys were cast and homogenized Ni-Co-Cr-Mo alloys with 0, 312, and 612 nominal wt pct molybdenum concentrations. The Gamma Prime Alloys were wrought and heat-treated Ni-Cr-Mo-Al(Ti) alloys with 0, 2, 5, and 8 nominal wt pct molybdenum in each of four aluminum plus titanium levels (3 pct Al, 412 pct Al, 6 pct Al, or 1 pct Al + 312 pct Ti nominal wt pct). Thermal expansion coefficients were determined on at least two specimens from each alloy. It was found that molybdenum lowers the thermal expansion coefficients of both the cast Ni-Co-Cr solid solutions and the wrought Ni-Cr-Al(Ti) two-phase alloys. Both aluminum and titanium were also observed to decrease expansion coefficients in the two-phase, γ + γ, alloys. Results are discussed in terms of relative melting point effects between solute and solvent elements, and in terms of the volume fraction of the γ phase present.