大块金属玻璃形成能力的研究进展

综述了近年来所发现的表征大块金属玻璃形成能力的参数,其中包括基于动力学、液相稳定性和抗晶化能力、物理结构参数、液相稳定性和原子尺寸结构、价电子浓度和有序相与无序相的竞争.指出了大块金属玻璃形成能力研究的复杂性,以及理论基础的重要性.     

Mg基大块金属玻璃的形成能力与形成机制

研究了新型多组元Mg基Mg-Ln-TM大块非晶合金玻璃转变行为，包括非晶固体与过冷液体之间的比热容差和明显的玻璃转变现象、过冷液相区的宽度以及过冷液体的黏性行为等。通过对玻璃转变行为与玻璃形成能力之间关系的分析，展示了Mg基大块金属玻璃较强的玻璃形成能力，从合金的结构、热力学和动力学形成条件等方面系统地讨论了Mg基大块金属玻璃的形成机制。     

Nb对Zr基块体金属玻璃形成能力与显微硬度的影响

研究Nb元素掺杂对zr基块体金属玻璃非晶形成能力与显微硬度的影响.采用水淬法制备直径13mm、长度为50-70mm的zr基块金属玻璃.金属玻璃成分为(Zr(41.2)Ti(13.8)Cu(12.5)Ni(10)Be(22.5))(100-x)Nb(x)(x=0,0.1,1,2,3,5).当Nb元素掺杂量x=5时,XRD和DSC证实所制备样品仍为全非晶.少量Nb的掺杂(x=1)能够显著提高合金的玻璃形成能力(GFA),合金的过冷液相区宽度由掺杂前的77℃提高到90℃.适量Nb元素的掺杂同时会造成金属玻璃显微硬度的提高.非晶晶化途径的改变是造成BMG热稳定性和玻璃形成能力提高的主要原因.     

浙江大学研制成功新型大块稀土基金属玻璃材料

日前，浙江大学新结构材料国际研究中心蒋建中教授组织开发了目前世界上尺寸最大的稀土基金属玻璃材料——直径为35毫米的镧基金属玻璃体系。其博士生曾桥石以第一作者的身份在《美国科学院院刊》发表了大块金属玻璃材料在14GPa（1GPa相当于1万个大气压）压力出现一个压缩率突变的新现象的文章。     

用沙坝矿中深孔爆破参数优化研究

开磷集团用沙坝矿采用皮带运输系统出矿,由于爆破参数等采用不合理,导致矿石块度不均匀,大块率较多,进而影响到开采能力。针对这种情况,通过理论计算和现场工业试验,采用小抵抗线逐孔起爆技术,确定合理微差时间及炮孔堵塞长度,获得了最优的爆破参数,从而减少了大块率,保证了皮带运输系统出矿的稳定性。     

改善岩体深孔爆破大块率的实践

通过对岩体深孔爆破大块产生的部位和原因的分析,提出了降低大块率的技术措施,指出根据岩体结构和岩性特征对爆破参数进行优化设计是控制大块率的关键环节,同时系统地论述了爆破参数设计的原则和程序,对改善深孔爆破大块率有借鉴意义。     

改善岩体深孔爆破大块率的实践

通过对岩体深孔爆破大块产生的部位和原因的分析,提出了降低大块率的技术措施,指出根据岩体结构和岩性特征对爆破参数进行优化设计是控制大块率的关键环节,同时系统地论述了爆破参数设计的原则和程序,对改善深孔爆破大块率有借鉴意义。     

含有等轴枝晶的塑性大块金属玻璃复合材料

利用低压铸造/水冷铜模急冷成形装置,翩备Zr56.2Ti13.8Nb5.0Cu6.9Ni5.6Be12.5大块金属玻璃(BMG)基体内生复合材料.铸态试样外观尺寸为50mm×50mm×3mm,具有bccβ-Zr固溶体/玻璃基体两相微观组织.其中,β相为细小等轴状树枝晶,体积分数约20%,平均成分为Zr64.66Ti15.40Nb15.13Cu2.90Ni19.0.DSC曲线显示,基体的玻璃转变温度(Tg)、晶化反应开始温度(Tx)和过冷液相区宽度(△Tx)分别为619,664和45K.室温压缩时,复合材料断裂前的纯塑性应变达到7%,并具有1800MPa的极限断裂强度.     

世界各国积极研制非晶金属

我国从 1976年开始非晶态合金的研究工作 ,现已初步形成非晶态合金科研开发和应用体系 ,共取得 10 0多项科研成果和2 0多项专利。“九五”期间 ,组建了“国家非晶微晶合金工程技术研究中心” ,建立了“千吨级非晶带材生产线” ,非晶态合金的产业化进程大大加快。大块金属玻璃在学术及应用上的重要性在国际上引起了广泛的关注 ,成为材料和物理领域的前沿课题之一。块体金属玻璃研究是日本文部省 1998年最大的研究项目 ;美国陆军 2 0 0 0年批准了一项 30 0 0万美元的研究计划 ;欧共体 2 0 0 0年也专门立项 ,组织欧洲十个重要实验室联合攻关。…     

北河地下矿山大块控制劈裂爆破技术研究

北洺河地下铁矿巷道内遗留大块难以高效处理,利用面对称金属聚能罩实现对大块的快速劈裂,在铁矿巷道内对大块进行了6组爆破试验,对比0、1倍炸高,2倍炸高时的块度分布、平均块度和爆破形态,研究了聚能装药参数中炸高、炸药单耗对大块破碎效果的影响.结果表明:无炸高时,碎块主要分布在大尺寸60～80 cm区间内;随着炸高的增加,碎...     

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     

Annual Report analysis of Chinese rare earth-related listed companies in 2013

<正>Chinese rare earth-related listed companies have published their 2013 annual reports.It can be understood from their reports that production and operation activities of Chinese rare earth-related companies were still heavily affected by macro economy and industrial policies.They basically followed the steps of national economy.In 2013,world economy recovered slowly but the economy     

Market opportunities and challenges for rare earth polishing powder

正1.Status of rare earth polishing powder Rare earth polishing powder with high content of cerium oxide began to replace iron oxide for glass polishing and became one of the key materials in glass polishing process since 1940.Compared with traditional iron oxide,rare earth polishing powder has many advantages,such as fast polishing rate,high polishing quality and long service life.It can achieve good surface quality and improve operation conditions.For example,in lens polishing,the polishing work that cerium     

Baotou Research Institute of Rare Earths developed a new RE alloy preparation technology

正Pyrometallurgy Laboratory of Baotou Research Institute of Rare Earths had independently developed a new preparation technology of rare earth alloy for NdFeB.The alloy can remarkably enhance the coercivity of NdFeB magnet but also evidently reduce the production cost of the magnet.The new master alloy was prepared in the kA pilot-scale electrolytic cell by the independent technology.The rare earth master alloy can be used as the raw material for NdFeB.Compared     

Market and recycling of NiMH battery

<正>Market status and future trend of NiMH battery1.Global market of small NiMH battery Global market size of small NiMH batteries declined year on year since 2011.The trend will continue to 2018,at the rate of 5%to 10%annually.Demand for small NiMH batteries will be stable gradually.Many electrical apparatuses are powered by the built-in lithium battery today,which is the main reason for the shrunk market of small NiMH batteries.But,for some products,small NiMH     

China rare earth market review

正September 1-10,2014 Affected by the National Day holiday,rare earth transaction was stagnant and the market showed a weak steady state.As there was no good news for downstream market,some products with flat demand would likely rally slightly for some time to     

2014 second batch of rare earth quota released

正~~     

矿用防爆轴流对旋主要通风机叶片ANSYS模态分析及应用

高效节能矿用防爆对旋主要通风机的叶片是主要通风机运行的关键部件,叶片在运行时不断受到气流的作用力,从而使叶片产生振动,当叶片振动的频率与叶片的固有频率接近时,容易产生共振从而导致叶片的断裂。一旦叶片断裂时,对主要通风机的安全运行产生致命的影响,从而导致矿山、化工等企业发生重大事故,将会产生不可估量的损失。基于有限元分析软件ANSYS,对高效节能矿用防爆轴流对旋主要通风机叶片进行模态分析及产生对应的六阶模态频率,对主要通风机叶片的运行频率、固有频率及产生的共振问题进行了原理分析,并且解决了叶片频率共振的问题,从而为主要通风机叶片结构设计提供理论依据,并对主要通风机叶片的安全运行提供保障。     

2013 NdFeB export analysis

<正>China totally exported nearly 24,000 tonsof NdFeB products during 201 3,including 18,825 tons of permanent magnet,valued USD 1.34 billion at an average price of 71.4 USD/kg;3,277 tons of NdFeB magnetic powder,valued USD 1 01 million at an average price of 30.9 USD/kg;1,334 tons of strip casting ribbon,with total export value of USD 74million at an average price of 55.3 USD/kg;and 586