Ar气流量对石墨表面CVD TaC涂层生长与表面形貌的影响

用C3H6作为碳源气,Ar作为稀释气体和载气,TaCl5为钽源,采用化学气相沉积法(chemical vapor deposition,CVD)在高纯石墨表面制备TaC涂层。采用X射线衍射(XRD)和扫描电镜(SEM)等对涂层进行表征,研究1 000℃下稀释气体(Ar)流量对TaC涂层成分、织构及表面形貌的影响。结果表明:随着稀释气体流量增大,表面均匀性和光滑度提高,晶粒尺寸减小,晶体择优取向降低,沉积速率减小,涂层中C含量增多。当稀释气体流量为100 mL/min时,TaC涂层晶粒尺寸与沉积速率分别为32.5 nm和0.60μm/h;而当稀释气体流量增大到600 mL/min时,涂层晶粒尺寸与沉积速率分别下降到21 nm和0.25μm/h。     

不锈钢基体表面CVD-Ta涂层组织和性能的研究

介绍了化学气相沉积(CVD)制备难熔金属Ta涂层的一般原理及方法。利用TaCl_5-H_2-Ar反应体系,采用化学气相沉积法在不锈钢基体表面沉积了Ta涂层。通过X射线衍射仪(XRD)和扫描电镜(SEM)手段,研究了CVD温度对Ta涂层的结构、沉积速率、显微组织的影响,分析了Ta涂层的显微组织结构和成分组成,对Ta涂层试样在强酸冲刷条件下进行了耐腐蚀试验,最后对Ta涂层试样的失效机理进行了分析。结果表明:在1000～1200℃范围内,随着沉积温度的升高,Ta涂层晶粒结晶性能逐渐变好,沉积速率逐渐增大,当沉积温度大于1100℃,Ta涂层和基体之间会出现较明显的扩散层;Ta涂层主要由分布均匀的钽元素和少量不连续的氧元素组成;涂层的失效的主要原因是由于Ta涂层纵向生长的柱状晶不致密,使得晶界处的氧化物率先腐蚀,使得钽涂层逐渐失去对基体的保护作用。     

SiC晶须的原位生长及其在C/C复合材料抗氧化涂层中的应用

以三氯甲基硅烷(CH3SiCl3,MTS)为先驱体原料,采用化学气相沉积法在C/C复合材料基体上原位生长碳化硅晶须(SiCw),制备CNT-SiCw抗氧化涂层,并在1 100℃、空气中对该氧化涂层进行10 h抗氧化实验,研究SiCw的制备工艺以及SiCw在C/C复合材料抗氧化涂层中的作用。结果表明:制备碳化硅晶须的最佳工艺为:温度1 100℃、常压、载气和稀释气体流量均为100 mL/min。在此工艺下,沉积时间为15 min时,能制备出高长径比、平均直径约100 nm的碳化硅晶须。有CNT-SiCw涂层C/C复合材料试样在空气中氧化后的质量损失率仅0.7%,没有涂层的试样的质量损失率约为15%。     

中密度C/C复合材料表面制备SiCnw/SiC涂层

在中密度C/C复合材料基体上采用催化化学气相沉积方法生长碳化硅纳米线(SiCnw)及制备碳化硅纳米线/碳化硅(SiCnw/SiC)涂层,研究中密度C/C复合材料基体上加载催化剂后涂层沉积及其抗氧化性能,结果表明:中密度基体上催化制备SiCnw涂层,可改善沉积效率,同时可抑制裂纹扩展,明显改善SiC涂层在1200℃的氧化防护能力。另外,在1500℃的空气中氧化10h后,SiCnw/SiC涂层氧化质量损失率仅为1.34%,明显低于质量损失率为8.67%的单层SiC涂层。     

CVD温度对钽涂层组成、显微组织及形貌的影响

利用TaCl2-H2-HCl反应体系,采用冷壁式化学气相沉积法(CVD)在钼基体表面沉积钽涂层。通过X射线衍射仪、金像显微镜及扫描电镜等手段,对不同沉积温度下钽涂层的组成、组织及形貌进行了研究。结果表明:在1000～1300℃范围内,钽沉积层的相组成无变化,而对择优生长有一定影响;钽沉积层晶粒尺寸随沉积温度的升高而增大;钽沉积层表面颗粒呈金字塔形多面体且随沉积温度的升高而增大。     

硬质合金PVD涂层技术的发展

本文简要介绍了世界发达国家PVD(物理气相沉积)涂层刀具的发展趋势。对可用于硬质合金涂层的三种PVD技术、涂层的组织结构特征、性能进行了评述,同时与未涂屡、CVD(化学气相沉积)涂层作了比较。     

沉积温度对SiC涂层微观结构及组成的影响

利用MTS-H2-Ar体系，用化学气相沉积法（CVD）在SiC基体材料表面沉积SiC涂层。用X射线衍射仪和扫描电镜分析涂层的晶体结构和表面形貌。研究温度对涂层的物相组成、微观结构和沉积速率的影响。结果表明：在1100～1400℃范围内，沉积产物均为单一的β-SiC结晶相；随温度升高，SiC晶粒尺寸增大，1400℃时择优生长由（110）晶面转变为（220）晶面；涂层形貌对温度十分敏感，在1200℃温度下沉积的涂层最为致密，且具有最大沉积速率，是制备SiC涂层的最佳温度。     

热解碳沉积温度对增强石墨力学性能的影响

采用化学气相沉积增密技术制备热解碳增强普通石墨材料。研究沉积温度对增强石墨力学性能的影响,并探讨热解碳增强普通石墨材料的沉积机理。结果表明:随沉积温度升高,增强石墨的抗弯强度提高,在1 600℃沉积时达到最大值39.33 MPa,比石墨基体提高21.7%。其主要原因是随沉积温度升高,热解沉积由CVI过程变为CVD过程。当温度低于1 600℃时,化学气相渗透过程占主导;温度高于1 600℃后热解碳极易沉积在基体表面,形成热解碳膜,化学气相沉积过程占主导。在1 600℃温度下,其抗弯强度随沉积时间的变化不大,这证明高温下(1 600℃)化学气相沉积主要发生在石墨块体表面。     

热等静压(HIP)对CVDZnS光学性能的影响

对化学气相沉积(CVD)ZnS经热等静压(HIP)处理前后在光学透过率等方面的改变进行了比较分析。针对温度、原生样品厚度等因素对样品性能的影响做了详细阐述。实验表明，热等静压对原生CVDZnS光学性能有促进作用，随处理温度的升高，透过率在1010～1050℃之间出现峰值；原生样品厚度的影响不容忽视，导热均匀的薄样品晶粒均匀且尺寸较大，光学及力学性能要好于厚样品。     

刀具涂层技术的研究现状和发展趋势

结合近年来刀具涂层技术的发展状况,介绍了各种刀具涂层材料,结构以及制备方法。将涂层材料分为硬涂层与软涂层进行了介绍。综述了各种涂层结构。刀具涂层的制备方法包括化学气相沉积法（CVD）、物理气相沉积法（PVD）、等离子体化学气相沉积法（PCVD）和溶胶-凝胶法（Sol-Gel）等。介绍了刀具涂层工艺的研究现状,并对刀具涂层的发展方向进行了探讨。     

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.