泡沫铝用Ni/TiH_2包覆型发泡剂的制备工艺及性能

TiH2是熔体发泡法制备泡沫铝最常用的发泡剂,为了延缓TiH2在发泡初期的分解速度,获得均匀的泡沫材料,以硫酸镍(NiSO4·6H2O)为主盐,联氨(H2N-NH2·H2O)为还原剂,采用化学镀的方法,通过控制反应条件,在氢化钛(TiH2)表面均匀地包覆质量比可控的单质Ni层.实验得到了氢化钛表面镀镍的优化工艺参数,与纯TiH2粉末相比,所得Ni含量为50%的Ni/TiH2复合粉末可推迟缓释氢时间达70 S,使整个释氢时间比包覆前延长100 S.     

高压氢还原法制备Ni包SiC粉末的研究

采用高压氢还原法制备了Ni包SiC复合粉末,研究了反应温度、氢分压、表面活性剂及包覆次数对包覆效果的影响,并且对该包覆粉末的热稳定性进行了评价。结果表明:在反应温度为150~160℃、氢分压为1.5~2.5MPa、活性剂的质量浓度为0.05g/L、搅拌速度为800r/min的条件下,包覆二次可以获得连续均匀的包覆层。包覆粉末在1 150℃左右会发生反应,生成Ni2Si和C。     

化学镀镍对Ti粉吸气性能的影响

采用低温碱性化学镀方法制备镍包覆钛复合细粉，利用XRD，SEM，EDS和吸气性能测试台对样品的相结构、表面形貌、表面成分和吸气性能进行分析和表征。结果表明：表面镍层以结晶态包覆于Ti表面，镀层均匀，镀层中的Ni对H2具有催化解离作用，促进了Ti的吸氢速率，在较低温度450℃激活时，镍包覆钛复合细粉的吸氢性能较纯Ti粉有了明显的提高。     

纳米Si_3N_4/Ni复合镀层对金刚石节块性能的影响

用滚镀的方法在金刚石表面镀Ni层和纳米Si_3N_4/Ni复合镀层,用扫描电子显微镜观察金刚石镀前和镀后的表面形貌,用DKY-1型单颗粒抗压强度测定仪测量金刚石单颗粒的抗压强度。用热压烧结的方法得到铁基结合剂金刚石节块,在INSTRON-5569型万能材料试验机上测量节块的抗弯强度,在NMW-1立式万能摩擦磨损试验机上测试节块的耐磨性。结果表明:在金刚石表面镀Ni层和纳米Si_3N_4/Ni复合镀层后,表面镀层均匀,纳米Si_3N_4/Ni复合镀层比纯Ni层更致密,更平滑,晶粒更细小;纳米Si_3N_4/Ni复合镀层金刚石单颗粒有更高的抗压强度;纳米Si_3N_4/Ni复合镀层金刚石铁基结合剂节块有更高的抗弯强度和更优良的耐磨性。     

不同粒度钨粉化学镀铜的研究

通过化学镀可以在钨粉颗粒表面均匀包覆铜层,从而改善钨铜合金的组织和性能.本文首先确定了钨粉化学镀铜的镀液温度,在此基础上研究了钨粉粒度对钨粉表面化学镀铜工艺的影响.分别采用XRD和SEM来分析W-Cu复合粉体的相组成和钨粉镀覆前后形貌及均匀性,以施镀同样重量的铜粉所需时间来描述镀速的相对快慢.结果表明:钨粉化学镀铜的适合镀液温度为45℃,此时镀速快,镀液稳定不分解,铜镀层致密;随着钨粉粒度变粗,镀速变慢,施镀时间延长,并且过粗的钨粉在镀液中不易悬浮,镀铜不充分;不同粒度的钨粉化学镀后都包覆一层成分单一的致密铜层,化学镀包覆的铜层是晶态的.     

金刚石盐浴镀覆温度对Al/金刚石复合材料导热性能的影响研究

采用盐浴镀对金刚石颗粒进行表面镀Ti,并采用放电等离子烧结制备高导热Al/金刚石复合材料,探讨了镀覆温度对金刚石表面镀Ti层结构、成分以及Al/金刚石烧结体导热性能的影响。结果表明,在较低的温度(700℃)镀覆30min即能够使金刚石表面包覆一层较为均匀的镀Ti层,镀层表面光滑平坦。当镀覆温度升高,金刚石不同类型表面呈现不同的镀层形貌。Ti在金刚石(100)面沉积速率要高于(111)面,表明金刚石(100)面比(111)面活性更高。随着金刚石镀Ti温度的提高,Al/金刚石复合材料的热导率逐步下降。相比之下,700℃镀覆温度下所得金刚石表面镀层较薄,而且镀层与金刚石之间结合力较强,SPS烧结过程中金刚石与Al基体能够实现较为紧密的结合,因而复合材料热导率优于其它更高镀覆温度条件下所制备的Al/金刚石复合材料。     

化学镀法制备镍包石墨复合粉末

采用化学镀法在石墨粉末表面镀镍制备Ni/石墨复合粉末,采用激光衍射粒度分析、扫描电镜等对Ni/石墨复合粉末的粒度和表面形貌进行表征,研究镀液中主盐硫酸镍、还原剂联氨及活化剂氯化钯的浓度对该复合粉末表面形貌的影响,并对Ni镀层在石墨表面的生长机理进行探讨.结果表明:硫酸镍质量浓度为20 g/L、联氨体积分数为2％时,化学...     

热处理对钛表面Ni—P合金镀层性能影响的研究

研究了钛表面Ni—P合金镀层的热处理工艺,通过分析镀层的表面形貌及物相组成,探讨了热处理温度等关键因素对Ni—P合金镀层硬度的影响。研究结果表明,在300℃热处理时,电镀时间为1h的镀层中只有Ni5P4相和M,无Ni3P相,电镀时间为2h和3h的镀层中仅有少量的Ni3P相;在400℃热处理时,镀层均由大量Ni3P相和微量Ni组成;400℃热处理后的镀层硬度高于镀态和300℃热处理后的硬度;电镀时间为2h,热处理温度为400℃时,Ni—P镀层硬度最高,维氏硬度达到8938MPa。     

碳纤维电镀Cu/Ni双镀层及其性能表征

碳纤维经过脱胶和活化预处理后,表面活性大大增加,碳纤维表面由疏水性转变为亲水性,电镀过程中能很好地在镀液中润湿、分散,可解决碳纤维电镀常易出现的"黑心"问题。通过对照实验,确定最佳电镀工艺:镀Cu温度为45℃,电流密度为0.7 A/dm2;镀Ni温度为25℃,电流密度为0.8 A/dm2。碳纤维经连续电镀后得到Cu/Ni双镀层。测试结果表明:双镀层均匀致密,界面结合良好,镀层纯度高,结合力强。电镀前后单丝拉伸性能基本无改变,可很好地保持碳纤维的力学性能。电镀后碳纤维电阻率急剧下降,导电能力显著增加。     

Al_2O_3预包覆尖晶石LiMn_2O_4的电化学性能

将Li2CO3和电解二氧化锰混合球磨,得到尖晶石(LiMn2O4,简称为LMO)的前驱体,采用化学沉积法在前驱体的预烧产物表面包覆Al(OH)3,然后在750℃/6h条件下煅烧,得到Al2O3/LiMn2O4复合粉末(称为Al2O3预包覆,包覆粉末记为P-LMO);同时采用传统方法,在前驱体的煅烧产物(LiMn2O4粉末)表面包覆Al(OH)3,然后在300℃/3h条件下热处理,得到Al2O3/LiMn2O4复合粉末(称为煅烧包覆,复合粉末记为C-LMO),对这2种包覆法制备的Al2O3/LiMn2O4复合粉末的物相结构、形貌、包覆层的厚度与粒度分布等进行对比分析,并对包覆粉末进行电化学性能测试。结果表明,Al2O3均匀地包覆在LiMn2O4的表面,包覆层厚度约为10nm;Al2O3/LiMn2O4复合粉末的晶格常数随Al2O3包覆量增加而增加;预包覆粉末颗粒呈类球形,平均粒径(0.3μm)明显小于煅烧包覆的平均粒径(0.5μm);预包覆粉末的Al2O3包覆层能有效减少循环过程中电荷转移阻抗的增加,并减少Mn的溶解,其循环性能优于煅烧包覆粉末。在3.2~4.5V的充放电区间内,Al2O3包覆量(摩尔分数)为2%的预包覆LiMn2O4材料显示出优良的电化学性能,55℃下0.1C的首次放电容量为114.0(mA·h)/g,0.5C倍率下50次循环后容量保持率为87.3%。     

China's Major Non-ferrous Metals Imports & Exports

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Zinc Production by Province in 2014

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80% of Chinese Firms Purchasing Overseas Mines Ended up in the Red

<正>Minmetals Resources acquired the world’s largest copper mine under construction for USD5.85 billion.One after another,listed companies Jien Nickle,China Molybdenum and Chihong Zinc and Germanium raised money to get involved in overseas mining projects…SOEs and private enterprises are engaged in a frenzy of overseas mine purchasing.A reporter with Economic     

Copper Processing Profit Dropped Sharply,Copper Consumption Will Face Impact in the Second Half of the Year

正Judging from China’s copper consumption field,the biggest consumption unit is electric power,which accounts for 47%of total consumption;it is followed by light industry sector,including household electrical appliance,machinery,durable goods and hardware etc,which accounts for 22%of total consumption;followed by transportation field,     

Central Geological Prospecting Fund Newly Added 16.47 Million Tonnes of Bauxite in 2013

正In 2013,the Central Geological Prospecting Fund(CGPF)Project newly discovered 15 ore fields,including 3 large above ore fields,and 5medium sized ore fields.The reporter learned from the recently published"Annual Report of Central Geological Prospecting Fund Project(2013)"that,from 2006 to 2013 the CGPF     

Manufacturers of Copper Tube for Central Air Conditioner Use Face Mounting Pressure in the Final Quarter of the Year

正This year,the investment growth rate of real estate industry continued to slow down,sold area of commercial housing also dropped significantly,which brought huge pressure to the domestic air conditioning manufactures.In the first half of the year,by relying on high growth in national financial expenditure,along with investment in public infrastructure     

Xinjiang Ranks No.1 in Production of Primary Aluminum in China

正Kang Yi,Honorary Chairman of China Nonferrous Metals Industry Association,said recently at the Forum on Development of the Non-ferrous Metals Industry in Central and Western China held in Zhengzhou that,as more and more electrolytic aluminum factories in Xinjiang came into operation,the electrolytic aluminum output of Xinjiang had reached2,275,000 tons in the first 7 months this year,     

Shenhuo Coal Industry and Electricity Power Completed800,000 t/a Aluminum Project in Xinjiang

正"Xinjiang project has been completed according to schedule,but total completion and total start of production are two different concepts,after completion it still needs a gradual process of reaching production target."On the morning of November 3,Shenhuo Coal Industry and Electricity Power told investors the above statement on the investor interaction platform.     

Guangdong Metal Transaction Center has Become the Second Largest Precious Metal Transaction Platform Nationwide

正The reporter learned from Guangdong Province Precious Metal Transaction Center that in 2013the Center maintained healthy development momentum,and had become the second largest precious metal transaction platform in China in terms of market size;currently Guangdong is quickening steps of financial innovation for the Center,aiming to build a transaction center with international core competitiveness.     

Seven Rare Earth Projects Involving Close to 3 Billion Yuan Investment Landed In the HighTech Zone

正On May 22,Baotou Rare Earth Industry Cooperation Consultation MeetingProject Agreement-signing Ceremony was held in Ningbo,nearly 40 enterprises from Ningbo,Guangdong,Hunan,and Shanxi participated in project consultation.After multi-lateral communication,agreements were signed for a total of 7 rare earth projects successfully.