磷化助剂对铝合金磷化膜耐蚀性能的影响

采用锌系磷化液在中温条件下对铝合金进行磷化处理获得磷化膜。通过电化学测试方法分别研究了磷化助剂磷酸二氢铁、硝酸镍、柠檬酸、磷酸含量的变化对该磷化膜耐蚀性的影响。结果表明,当磷酸二氢铁含量为4g·L-1、硝酸镍含量为1.5g·L-1、柠檬酸含量为1.5g·L-1、磷酸含量为3.5g·L-1时,铝合金磷化膜的耐蚀性最好。     

锌系磷化的稀土促进成膜机理研究

能谱成分分析结果表明,加入稀土硝酸盐(REN)后磷化膜内P元素含量增大,Zn元素含量减小,而对磷化膜耐腐蚀性的贡献为P>Zn。由SEM形貌分析可获知,添加REN后无定形晶体Zn2Fe(PO4)2在磷化膜表面覆盖率有较大幅度提高,从而使得膜的P/(P+H)比率增大,磷化膜的耐蚀性能提高。机理研究则指出,稀土实质是一个有良好载氧能力的催化剂,具有良好的成核促进作用和阴极去极化作用,在磷化过程中同时发挥了表调剂、促进剂与致密剂的作用,加速了磷化过程,并使膜的耐腐蚀性能提高。     

稀土硝酸盐、亚硝酸钠和钼酸钠磷化对不锈钢表面的改善作用

提出在表面生成磷化膜以提高不锈钢的耐磨与耐蚀性能的工艺方法,讨论了各种促进剂(亚硝酸钠、钼酸钠、硝酸铈和硝酸镧)对磷化膜形成的影响,探讨了稀土对磷化的影响机理.结果表明,稀土元素对磷化的强化作用是明显的,其中Ce(NO3)3对提高不锈钢基的磷化速度与耐磨性能的贡献均较为显著,La(NO3)3对提高不锈钢的耐腐蚀性的贡献则较大.     

稀土抑菌作用研究

采用抑菌圈法研究了14种稀土离子对2种植物细菌和4种植物真菌的抑菌作用,稀土离子设5个浓度分别为:500mg·L-1、1000mg·L-1、2000mg·L-1、2500mg·L-1和3000mg·L-1.实验结果表明,稀土离子的抑菌作用随浓度的增加而增强,稀土离子的抑菌作用具有选择性,不同的稀土离子对同一种真菌的抑菌作用差异较大;同一种稀土离子对2种细菌的抑菌作用差异也较大.镧对玉米大斑菌、铕对小麦赤霉菌、铽对小麦根腐菌、镝对番茄灰霉菌、钬对玉米大斑菌、铥对小麦赤霉菌、镱对番茄灰霉菌和玉米大斑菌、钇对番茄灰霉菌及14种稀土离子对油菜黑腐菌具有较好的抑菌作用.     

锌表面稀土化学钝化及耐蚀性研究

采用三价铈盐对锌进行化学钝化处理 ,研究了有关工艺参数对锌表面稀土转化膜耐蚀性的影响 ,测量了钝化过程中试样的交流阻抗谱 (EIS)和表面显微硬度的变化 ,探讨了稀土转化膜的形成机理 ,并对成膜动力学进行了分析。随着钝化液的铈盐浓度、pH值、温度和处理时间的增加 ,稀土转化膜的耐蚀性也相应提高 ,一定条件下可达到或优于铬酸盐钝化的防蚀性能。稀土钝化成膜反应动力学符合Arrhenius方程 ,反应活化能约为 6 4 8kJ/mol。     

稀土对Al-Mg-Si合金氧化着色型材质量的影响

研究了稀土对6063合金(Al-Mg-Si合金)氧化着色型材氧化膜的光泽度、硬度、耐蚀性及膜层组织结构的影响。试验结果表明,加入适量稀土的6063型材氧化着色后,氧化膜的厚度、光泽度、硬度、耐蚀性都有明显增加。合金铸态组织细化且型材力学性能提高。     

模拟降雨下离子型稀土矿区坡面产流产沙与稀土迁移规律

通过野外模拟降雨实验,研究离子型稀土矿区坡面产流产沙的基本特征及稀土迁移的内在机制。结果表明:(1)总产流量和总产沙量分别为2971.3×10-3L、14.87×10-3kg,随着降雨历时的延长,产流率和产沙率均呈先增加后减少,再趋于稳定的变化趋势;累计产流量和累计产沙量随着降雨的持续进行先加速递增,后匀速递增,直至降雨结束,两者呈线性关系。(2)各降雨时段内径流和泥沙中的稀土含量分别在5.57 ug·L-1~20.33 ug·L-1、116.2 mg·kg-1~290.7 mg·kg-1范围内,径流和泥沙迁移的单位稀土含量和稀土总量分别为10.91 ug·L-1、32.42 ug,228.23 mg·kg-1、3393.79×10-3mg;在径流中表现为重稀土含量、重稀土迁移量高于轻稀土含量、轻稀土迁移量,而在泥沙中则呈现出相反的规律。(3)随着降雨历时的延长,径流和泥沙的稀土含量及稀土迁移量均呈先增加后减少,再趋于稳定的变化趋势。研究成果为揭示降雨过程中土壤侵蚀与稀土迁移对生态环境的作用机理提供了参考。     

镁合金微弧氧化研究

在两种体系中研究了镁合金的微弧氧化.对比实验表明,磷酸盐体系中钕对氧化膜外观、厚度和耐蚀性有较大改善,提高钕盐浓度效果更佳;硅酸盐体系中,用稀土盐溶液浸泡试样后,制得的试样表面颜色较白,膜层分布更均匀,起弧容易.两种体系中用稀土转化膜取代镁合金表面的自然氧化膜进行微弧氧化处理,获得的陶瓷层分布更加均匀,表面更光滑致密,耐蚀性显著加强.     

10PCuRE钢的耐大气腐蚀性及耐蚀机理

通过周期性浸润腐蚀试验对实验室冶炼的加稀土和未加稀土的Cu-P系耐候钢和A3钢进行了腐蚀性能的测定,结果表明:加稀土和未加稀土的Cu-P系耐候钢的耐蚀性均远远好于A3钢的耐蚀性,而加稀土的耐候钢比不加稀土的耐候钢的耐腐蚀性更好.通过极化试验、扫描电镜及能谱仪和X射线衍射仪等分析测试手段,对稀土耐候钢的耐蚀机理进行了研究,发现稀土通过使钢中的夹杂物变质使钢的耐蚀性提高,在腐蚀过程中稀土的存在有利于稳定的腐蚀产物α-FeOOH的形成,使耐蚀锈层更加均匀致密,因此提高了钢的耐蚀性.     

无铬达克罗成膜物质的研究进展

无铬达克罗是通过无铬钝化技术在金属材料表面形成的耐腐蚀性能佳、环境污染小、对人体健康几乎没有危害的金属表面防护膜层.本文综述了国内外形成这种膜层的物质的研究进展,展望了无铬钝化技术的发展趋势;在总结与分析的基础上指出:随着环境保护要求的提高,有机聚合物(硅烷或树脂)和稀土盐(铈盐)组成的复合成膜体系有着较好的开发和应用前景.     

熔炼次数对M17返回料合金成分、组织和性能的影响

实验结果表明,M17铸造高温合金(%:0.16C、8.79Cr、5.79A1、4.93Ti、3.29Mo、15.20Co、0.78V、0.015B、0.073Zr、0.002S、0.001P、0.001 1O、0.001 0N)经25 kg真空感应炉返回重熔后,Si含量随重熔次数的增加而略有增加,合金中主要元素和其它杂质元素S、P、H的含量变化不大,而氧、氮略有增加;合金中初生碳化物由新合金中的草书体逐渐向返回合金块状转变,初生碳化物的遗传性堵塞合金凝固时的补缩通道,使返回料合金的疏松倾向增大,高温塑性下降较大。     

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.