Fe-50%Ni注射成形的溶剂—加热两步脱脂工艺

采用高能球磨法将羰基铁粉和羰基镍粉混合,对Fe-50%Ni合金粉末进行注射成形,研究以正庚烷为溶剂的溶剂一加热两步脱脂工艺,考察溶剂温度、粉末粒度对石蜡脱除率的影响。根据喂料的差热分析结果,确定合适的热脱脂温度。结果表明,当脱脂温度为60℃,脱脂时间为4 h时,石蜡脱除率可达95%。40℃时溶剂脱脂早期大粒度粉末的脱脂速度要比小粒度粉末的脱脂速度快,8 h后小粒度和大粒度粉末脱脂速度相同。溶剂脱脂提高脱脂效率,脱脂时间缩短3 h。     

注射成形Al2O3-10%Cu的脱脂工艺

Al2O3-10%Cu坯料采用注射成形制备,分别进行溶剂脱脂、热脱脂和溶剂-热二步脱脂研究。研究了不同溶剂配比对溶剂脱脂的脱脂率影响；根据粘结剂各组元的熔点和裂解温度区间,制定了合适的热脱脂工艺；从宏观、微观两方面研究了不同脱脂方法对脱脂效果的影响。结果表明：溶剂脱脂时溶剂采用三氯乙烯在40℃脱脂6h,脱脂率稳定在68.4%；采用溶剂-热二步脱脂的脱脂率提高至96.1%,且能减少脱脂缺陷。     

注射成形Al_2O_3-10%Cu的两步脱脂工艺

采用注射成形制备Al2O3-10%Cu坯料,研究溶剂脱脂—热脱脂两步脱脂过程。结果表明,溶剂脱脂时溶剂采用三氯乙烯在40℃脱脂6 h,脱脂率稳定在68.4%,随后热脱脂将脱脂率提高至96.1%。两步脱脂工艺能基本脱除粘结剂,可有效缩短脱脂时间,避免脱脂缺陷的产生,脱脂坯表面质量良好。     

水溶性MIM粘结剂的制备及性能表征

以PEG和POM为主体组分配方制备了一种用于金属粉末注射成型用的水溶性粘结剂.通过扫描电镜分析、差示扫描量分析仪、热重分析仪及热性能测试、脱脂率实验等对制备的粘结剂体系进行分析表征.结果表明:该粘结剂体系组分之间有很好的相容性,和金属粉末的混合性良好;该种粘结剂在水中脱脂速度快,脱脂率高,在75℃水中4h内的脱脂率43.06%;粘结剂体系具备良好的热分解性能,添加剂的加入使得热分解温度降低,有利于烧结的进行.     

金属注射成形脱脂技术研究

金属注射成形技术是近年来发展最迅速的粉末冶金近净成形枝术,其中脱脂技术是其整个工艺过程中最为关键的技术之一。总结了目前常用的几种脱脂方法(热脱脂、溶剂脱脂、催化脱脂、虹吸脱脂),并介绍了2种较为先进的脱脂方法:冷凝蒸汽脱脂法、超临界流体萃取脱脂法。     

掺杂EBS润滑剂的粉末冶金铝合金脱脂工艺

采用冷压—烧结工艺制备了掺杂乙撑双硬脂酰胺(EBS)润滑剂的粉末冶金铝合金,比较了单/多温段脱脂工艺的优劣,发现多温段脱脂优于单温段脱脂,脱脂更彻底,但由于气体流量不能无限大,导致气氛脱脂得到的样品碳含量无法达到碳剩余理论值0.02%。研究了真空脱脂和空气负压脱脂机制,真空脱脂可使得EBS热分解的气态有机物和灰分从压坯表面逸出,并被及时带出炉外,最终合金碳含量接近碳剩余理论值0.02%;空气负压脱脂可使得残余碳被氧化逸出,脱碳更彻底,样品碳含量低于碳剩余理论值。研究了脱脂工艺对合金力学性能的影响,发现真空脱脂合金力学性能优于气氛脱脂,相对密度最大为97.86%,拉伸强度最大为218.06MPa,接近未添加润滑剂合金的力学性能;空气负压脱脂虽然可使碳含量更低,但因脱脂过程中样品暴露在空气中,使得原料粉末也被氧化,导致合金最终的力学性能严重下降。     

镧锶锰氧球形颗粒脱脂行为的研究

以La₂O₃,SrCO₃和MnO₂为原料,采用搅拌球磨、喷雾干燥技术,制得结构不稳定的镧锶锰氧（LSM）球形颗粒,不稳定的LSM球形颗粒需要低温煅烧以排除颗粒内部的有机物．为了研究不稳定LSM球形颗粒脱脂过程中的行为变化,通过TGA-DSC法分析镧锶锰氧（LSM）球形颗粒中间体在0~1300 ℃之间的失重曲线和热量变化,初步确定脱脂温度范围,再结合实验确定脱脂温度、升温速率及脱脂时间等参数．研究结果表明：在脱脂温度为550 ℃、升温速率小于5 ℃/min、脱脂时间4 h条件下,脱脂后的镧锶锰氧（LSM）球形外貌不会被损坏,且中间体中的有机物得以有效脱出．     

CaCl2-CaF2熔盐的脱水工艺及性能研究

采用真空脱水工艺对CaCl_2-CaF_2熔盐进行处理,研究了脱水温度、脱水时间对CaCl_2-CaF_2熔盐中H_2O、CaO含量的影响,研究了不同粒度对吸水性能的影响以及金属铈溶解度和温度、时间的关系。结果表明,脱水温度500℃、脱水时间5 h时,熔盐中的H_2O、CaO含量最低;温度800℃、保温时间2 h制备的熔盐中的H_2O0.05%、CaO0.02%;金属铈在熔盐中的溶解度随着熔盐温度、溶解时间的增加逐渐增加;不同粒度的熔盐表现出不同的吸水性能,熔盐粒度越小,吸水性能越强。     

掺杂EBS润滑剂的粉末冶金铝合金脱脂工艺研究

文章通过冷压-烧结制备了掺杂EBS润滑剂的粉末冶金铝合金,比较了单/多温段脱脂工艺优劣,发现多温段脱脂优于单温段脱脂,脱脂更彻底,但由于气体流量不能无限大,导致气氛脱脂得到的样品碳含量无法达到碳剩余理论值0.02%。研究了真空脱脂和空气负压脱脂机制,真空脱脂可使得EBS热分解的气态有机物和灰分从压坯表面逸出,并被及时带出炉外,最终合金碳含量接近碳剩余理论值0.02%；空气负压脱脂可使得残余碳被氧化逸出,脱碳更彻底,使样品碳含量低于碳剩余理论值。研究了脱脂工艺对合金力学性能的影响,真空脱脂合金力学性能优于气氛脱脂,相对密度最大为97.86%,拉伸强度最大为218.06MPa,接近未添加润滑剂合金的力学性能；空气负压脱脂虽然可使碳含量更低,但因脱脂过程中样品暴露在空气中,使得原料粉末也被氧化,导致最终的合金力学性能严重下降。     

代汞缓蚀剂用氧化铟粉末的制备

采用沉淀法, 以精铟、硝酸、氨水为原料, 纯水为底液, 制备出了纯度、粒度和分散性良好的氢氧化铟沉淀物, 该沉淀物经过喷雾干燥、煅烧得到符合代汞缓蚀剂用粉末状氧化铟。沉淀法制备氧化铟粉末的适宜工艺为: 反应温度85 ℃, 硝酸铟溶液中铟离子浓度0.8 mol/L, 硝酸铟溶液滴加速度400 mL/h, 机械搅拌转速900 r/min, 煅烧温度850 ℃, 煅烧时间2 h。此工艺条件下所得氧化铟样品纯度高于99.99%, 粒度分布均匀, 各杂质含量符合国家标准, 满足电池代汞缓蚀剂的使用要求。     

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     

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     

2014 second batch of rare earth quota released

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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