失稳区A1-Li合金回归机制的计算机研究

基于离散格点形式的微扩散方程，对失稳区Al-Li合金在回归过程中Al3Li(δ’)相溶解做原子层面计算机模拟，分析析出相在回归过程中原子图像、序参数的演化，进而探讨Al-Li合金的回归机制。探明在失稳区Al-Li合金的回归过程有序相演化序列为：化学计量比δ’相→非化学计量比有序相→无序基体。失稳区合金的回归过程为“小范围的成分回落”，而时效过程为“大范围的成分起伏”，因此，在失稳区合金回归过程并非时效过程的逆过程。     

Cu,Li含量对新型超高强铝锂合金力学性能及微观组织的影响

利用力学性能测试和TEM分析测试手段,计算出铝锂合金Al-(3.6%~4.15%)Cu-(1.1%~1.4%)Li中非固溶Cu,Li原子摩尔分数总和及Cu/Li原子摩尔分数比,分析了强度和微观组织之间的影响机理.结果表明,合金中的主要时效强化相为大量T1相(Al2CuLi)和少量θ′相(Al2Cu),Li含量较高的合金可能析出的极少量δ′相(Al3Li).在上述成分范围内,随Cu含量或Li含量增加,合金强度提高,且Li含量的增加幅度不同,对合金强度的提高幅度存在明显的差异.非固溶Cu,Li原子摩尔分数总和及其比例共同作用,通过影响析出相总量、类型及各析出相分数决定合金强度.要获得铝锂合金的超高强度,在提高Cu,Li原子摩尔分数总和的同时,还要提高其比例.     

有序相临界晶核判据的计算机研究

利用微扩散方程对有序组成核过程进行计算机模拟，对经典理论的假设进行验证。新相胚牙不是经典成核理论假设的那样，在一开始就达到了化学计量比，而是在时效的过程吕，而是在时效的过程中，由非化学计量比逐渐向化学计量比演化。在演化过程中，有许多B位原子占位几率低而尺寸较大的胚芽因不稳定而消失，一些B位原子占位几率高的较小胚芽却稳定存在并继续长大。仅利用胚芽的尺寸作为临界晶核的判据并不充分，有序相临界晶核的判据应包括B位原子的占位几率。     

应力作用下1420Al-Li合金的腐蚀行为研究

通过动电位极化曲线、电化学阻抗谱,并结合SEM图,研究恒应力作用下1420Al-Li合金在3.5%NaCl溶液中的腐蚀行为.结果表明:随着应力增加,材料的腐蚀加剧;合金主要腐蚀类型为孔蚀,这是由于合金的主要时效强化相为δ'相(Al3Li),它作为阳极相均匀弥散分布在基体中,晶界处仅有少量的S(Al2MgLi)相.     

应力作用下1420Al—Li合金的腐蚀行为研究

通过动电位极化曲线、电化学阻抗谱，并结合SEM图，研究恒应力作用下1420Al-Li合金在3．5％NaCl溶液中的腐蚀行为．结果表明：随着应力增加，材料的腐蚀加剧；合金主要腐蚀类型为孔蚀，这是由于合金的主要时效强化相为δ’相（Al3Li），它作为阳极相均匀弥散分布在基体中，晶界处仅有少量的S（Al2MgLi）相．     

Al-Cu-Mg合金析出相的原子成键与性能

根据固体与分子经验电子理论（EET），计算Al-Cu-Mg合金时效初期形成的GPB区和S″相的价电子结构。结果表明，GPB区具有较强的共价键络，而S″具有较强的总共价成键能，这两种析出相的主体共价键络都对合金基体具有增强作用。同时从价电子结构层次和析出相中Al原子的总成键能力合理解释了GPB区演化为S和S相的相变机理，并说明了相变对合金的强化作用。     

时效析出对Al-Zn-Mg-Cu合金热稳定性的影响

采用透射电镜、常温力学性能测试等手段,研究了合金成分与回归再时效工艺对Al-Zn-Mg-Cu合金热暴露过程中力学性能和微观组织的影响。研究结果表明,GP区和η'相的粗化是导致铝合金热暴露过程中强度降低的主要原因。在120 ℃热暴露时,高度弥散分布的GP区有利于提高Al-Zn-Mg-Cu合金的热稳定性,而在150 ℃热暴露时,添加与空位有较高结合能的Zr和Ti元素可以降低溶质原子的扩散速度和析出相的粗化速度,抑制GP区向η'相的转变。     

Ni75AlxCr25-x合金时效组织演变行为微观相场模拟

利用三元微观相场动力学模型,结合原子图像、有序相颗粒半径和和体积分数等手段模拟研究不同浓度的Ni(75)Al(x)Cr(25-x)合金973K下的时效组织演变行为.结果表明,x=6,8,10三种Ni(75)Al(x)Cr(25-x)合金时效过程中均析出DO(22)和L1(2)两种有序相.随着Al含量的增加,L1(2)相颗粒的尺寸增大,体积分数增加,相应的DO(22)相颗粒的尺寸减小,体积分数减少.无论DO(22)相还是L1(2)相,在考虑弹性畸变能的影响后,有序相颗粒平均半径的立方与时间之间仅仅在粗化初期的某一阶段,近似的呈线性关系.整体I上来看,不满足LSW粗化理论.     

温度对Al-11.4%Li合金沉淀机制影响的微观相场模拟

利用微观相场法模拟Al-11.4%Li合金时效过程中的微观组织.从模拟结果可以看出,该合金在383,423和493K下沉淀机制分别为失稳分解,非经典形核与失稳分解的混合机制和非经典形核长大.随温度的升高,新相颗粒逐渐规则,溶质原子的簇聚程度以及体系整体的有序化程度都在不断的降低.     

铜铬合金时效早期阶段析出相的形貌和结构研究

用快速凝固法制备不同铬含量的三种铜铬合金粉体Cu-O.34Cr,Cu-O.76Cr,Cu-1.56Cr,并对合金进行时效,用高分辨电镜观察不同时效阶段的结构.在时效的前期阶段观察到两种长周期调制结构.调制结构I是在基体的晶体排列上加入了一个微小的调制形成的,是一个沿三个[111]晶向,周期为7～9的三维无公度调制结构.调制结构Ⅱ是典型的DO3型超结构,和基体具有N-W晶体学位向关系,能谱分析表明调制结构Ⅱ不是共格的BCC铬相,其成分组成[Cu]:[Cr]接近4:1.时效析出贯序可以表达为:FCC基固溶体(无序结构)→FCC演化的调制结构I→调制结构Ⅱ(典型的DO3结构)→BCC的Cr单质析出相.证明了过饱和铜铬合金时效过程的析出机制是以两个亚稳结构为过渡相逐步转变的,而不是"共格的Cr FCC相"或"共格的Cr BCC相".     

Current situation and future trend of China rare earth luminescent materialindustry(continued)

<正>Developing ecological lighting source The world is facing the big problem of energy shortage today and the contradiction between economy development and environmental protection is worsened.Therefore,people are more likely to choose an ecological light source that is more energy efficient and environmental friendly.The choice provides great opportunity for the development of rare earth optical material industry in China.The concept of green lighting positions rare earth luminescent material as a leading player in illumination market.The light source of both rare earth luminescent lamp and LED lamp is ecological and energy saving.This is why     

Galaxy Magnets achieved the net profit of 34.02 million yuan in the first six months of 2014

正Galaxy Magnet announced its financial results for the first half of 2014 on August 14.For the first six months ended on 30 June 2014,Galaxy Magnet achieved operation income of RMB 182.3 million,up8.40% over the same period of 2013,and the net profit attributable to the shareholders of the listed company of 34.02 million yuan,increasing 35.49% over the same period of last year.Stable performance increase was led by development of new customers and application market of magnets.     

Rare Earth Application in Steel in China

<正>China has rich rare earth resources.Output of rare earth and steel in China ranks the top first in the world.However,there is still certain distance between the steel produced in China and developed countries from the point of varieties and quality.China still has to import some types of steel.Improving the quality should be emphasiZed in future development of steel industry in China.Rare earth can be used to upgrade traditional steel     

China rare earth market review

正November 21~30,2014Due to weak demand from downstream industries,transactions of rare earth in Chinese domestic market were inactive.It was difficult to sell any rare earth products except for dysprosium oxide and terbium oxide.Suppliers lost confidence in recent market.Demand for rare earth products was soft.Consumers continued to take a wait-and-see attitude.Rare earth export market remained slow.     

稀散金属产业的观察与思考

分析了近年来国内外稀散金属产业的生产、应用、资源与市场状况.铟锡氧化物靶材、砷化镓晶片、锗红外材料、铼高温合金和硒在电解锰及玻璃的应用等已成为稀散金属的主要应用领域.稀散金属的产量快速增长达到历史高位而导致了市场的失衡.以GaInP_2/GaAs/Ge,CIGS和CdTe为代表的非硅系太阳能电池是稀散金属的新兴应用领域,将给稀散金属带来日益增长的需求.     

Current situation and future trend of China rare earth luminescent material industry

<正>Rare earth luminescent material is one of the most important application sectors of rare earths.China enjoys the exceptional advantage to develop rare earth luminescent material for its abundant rare earth resources.After several decades'endeavor,China's rare earth luminescent material industry,headed by rare earth phosphor for lamp and LED and high efficient rare earth energy-saving light source,has been gradually developed into a scale industry.China has become a major production base of rare earth phosphor for lamps and rare earth     

China rare earth market review

正June 1~10,2014Rare earth market remained weak.Quoted price of rare earth products was similar to that in May.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,polishing powder and ceramic industries remained inactive.Demand from downstream industry was soft.Consumers purchased on their needs.Suppliers had strong intention to sell.Prices of rare earth products     

Brief news

正Corun invested another 50 million yuan in power battery for HEV Hunan Corun announced on 27 June that they had signed the cooperation agreement to jointly built Corun(Shaoxing)Autos Power Battery System Co.,Ltd.in Shaoxing Binhai New City.According to the announcement,total registered     

铜熔炼中锍品位对杂质元素分配行为的影响

借助于多相、多成分系统中平衡计算的手段，开发出微量元素砷、锑、铋及伴生元素铅、锌等在铜熔炼中分配行为的计算机模型。利用该模型对铜熔炼过程进行计算机模拟，分析了冰铜品位对砷、锑、铋、铅和锌等杂质元素的分压、活度系数及它们在冰铜、炉渣和气相中分配率的影响，并讨论其热力学分析结果对生产实践的指导意义。     

New energy vehicle:an opportunity for rare earth magnets

<正>Extracted from Securities Guide 1.Popularity of new energy vehicles—an irresistible market trend1.1 Progress of new energy vehicles Chinese Premier Li Keqiang said recently on a visit to Xi'an BYD Autos that new energy vehicles,especially new energy bus,can lessen environment and noise pollution.He encouraged the use of new