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。     

球磨工艺对Ti/HA生物复合材料性能的影响

采用不同球磨介质对Ti+30％HA(质量分数)粉料进行高能球磨,随后在1000℃氩气气氛中热压,研究了球磨工艺对Ti／HA生物复合材料性能的影响。结果表明:随着球磨时间的延长,复合材料的致密度略有下降,硬度上升。热压后,Ti基体形成连通的网络,HA弥散分布于Ti基体中。干磨工艺条件下,球磨时间越长,显微组织越细;湿磨工艺条件下,较短的球磨时间,即可达到较好的细化弥散效果。因此,采用高能球磨,可使Ti／HA生物复合材料在较低的温度下致密化。此外,湿磨介质的存在有利予在短时间内得到力学性能和生物活性较好的Ti／HA生物复合材料。     

原始粉料的球磨工艺对Ti/HA生物复合材料性能的影响

采用不同球磨介质对Ti 30％HA配比的粉料进行高能球磨，随后于1000℃氩气气氛中热压，研究了球磨工艺对Ti／HA生物复合材料性能的影响。结果表明：随着球磨时间的延长，复合材料的致密度略有下降，硬度上升。热压后，Ti基体形成连通的网络，HA弥散分布其中。干磨工艺条件下，球磨时间越长，显微组织越细；湿磨工艺条件下，较短的球磨时间，即可达到较好的细化弥散效果。因此，采用高能球磨，可使Ti／HA生物复合材料在较低的温度下致密化，同时，湿磨介质的存在，有利于在短时间内得到力学性能和生物活性都较好的Ti/HA生物复合材料。     

Zr、Ti元素掺杂对高比重W-Cu-Ni/Y2O3复合材料的显微组织和性能的影响规律研究

通过高能球磨法制备了多元掺杂高比重W-Cu-Ni/Y2O3粉末,经放电等离子烧结制得高比重W-Cu-Ni/Y2O3复合材料,研究分析了材料显微组织、晶体结构和力学性能.结果表明:掺杂质量分数1.5％Zr、1.5％Ti元素所制备的粉体具有良好的烧结性能,经SPS烧结后相对密度超过99.5％.同时,所制得的复合材料具有更好...     

离心-凝胶注模技术制备Ti/HA梯度复合材料

利用离心-凝胶注模成形技术制备Ti/HA梯度复合材料。研究了固相含量和Ti含量对Ti/HA浆料粘度的影响,分析了引发剂和催化剂含量对浆料凝胶固化时间的影响。测定了不同离心转速、离心时间以及浆料固含量下的Ti/HA复合材料生坯各部位密度,进而研究离心成形过程Ti和HA颗粒的物质分离现象。利用SEM观察了烧结后Ti/HA梯度材料各部位的显微组织,并测定其抗弯强度和断裂韧性。结果表明,固相含量为50%、Ti含量为7%的Ti/HA浆料具有较低的粘度232.1 mPa·s,当加入1.2%引发剂和0.9%催化剂时,该浆料起始凝胶固化时间为10 min。该浆料在1 000 r/min转速下离心10 min后所得的Ti/HA生坯具有良好的密度梯度;该生坯在1 000℃下烧结2 h后,Ti/HA复合材料显微组织中Ti颗粒呈良好的梯度分布,其抗弯强度和断裂韧性分别为82.2 MPa和1.71 MPa·m~(1/2),比纯HA材料提高了153%和116%。     

机械球磨与放电等离子体烧结制备碳纳米管/铜复合材料

采用机械球磨和放电等离子体烧结(SPS)工艺制备了碳纳米管(CNTs)/铜复合材料.利用SEM和TEM对材料组织和形貌进行了表征,研究了球磨时间、CNTs含量、SPS烧结压力对复合材料组织和性能的影响.结果表明:质量分数为1％的CNTs可在铜基体中获得良好分散;CNTs与铜基体界面结合良好,有利于应力在基体与CNTs之...     

SPS法制备Al2O3/Cu复合材料研究

将纳米级A12O3以体积分数为1％的配比与微米级Cu粉混合均匀后,采用放电等离子烧结(SPS)法,分别在750、800和850℃进行烧结制备复合材料;将同样的混合粉末采用冷压烧结制备复合材料作为对比.分别测试材料的密度、硬度、导电率,并进行SEM扫描电镜分析.结果表明:在所选择试验参数下,烧结温度为800℃ SPS烧结试样具有最高的相对密度,达到99.17％,硬度与导电率也最高;与冷压烧结制备的材料相比,SPS法制备的试样硬度和导电率更高;SPS烧结试样晶粒均匀细小,并出现了孪晶.     

SPS烧结钛固溶体致密陶瓷TiO_xC_yN_z的研究

以TiO、TiC和TiN的商业粉末为原料,采用放电等离子烧结技术(SPS)在1 600℃制备致密的钛固溶体Ti3OCN,系统研究了不同烧结方式下(包括SPS、传统烧结(CS)和它们的组合)烧结Ti3OCN的致密化过程和性能变化。结果表明,制备的Ti3OCN具有面心立方结构,其形成机理是O、N元素进入TiC。在SPS之后进行的CS过程可以小范围地增加钛固溶体的密度和电导率,但会降低其机械性能。     

石墨烯/Ti60复合材料组织与力学性能研究

石墨烯与Ti60合金粉末经过球磨混合后，采用放电等离子烧结法(SPS)制备出石墨烯/Ti60复合材料，并在900℃对其进行热轧加工。采用扫描电子显微镜(SEM)、能谱仪(EDS)、金相显微镜和万能试验机对烧结态与轧制态Ti60合金、石墨烯/Ti60复合材料的微观组织和力学性能进行分析。结果表明：添加质量分数为0.1%的石墨烯能够减小复合材料原始β相尺寸，增大α相尺寸。经热轧加工后，石墨烯/Ti60复合材料在室温、600℃和700℃的抗拉强度分别为1353.0、746.6和391.7 MPa,相比Ti60合金分别提高了9.24%、9.46%和2.99%。     

金刚石/Cu复合材料的烧结致密化研究

金刚石/Cu复合材料是性能优异的新型高导热低膨胀热管理材料.采用金刚石经表面镀Ti或Cr后再镀Cu, SPS烧结制备金刚石/Cu复合材料.结果表明: 金刚石/Cu复合材料的烧结致密化与金刚石的体积分数、粒度大小、烧结温度及形成的金刚石/金属间的界面相关.金刚石的体积分数对烧结致密化影响最大, 烧结温度影响最小; 随金刚石体积分数和粒度的增加, 金刚石/Cu复合材料的烧结致密化难度增大.     

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.