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碳化硅晶须补强氧化铝复合材料的制备及其力学性能 总被引:5,自引:0,他引:5
本论文利用商用γ-Al2O3粉体和上海硅酸盐所制备的碳化硅晶须,通过热压工艺来制备碳化硅晶须补强氧化铝复合材料.当晶须含量为30vol%时,室温下复合材料的抗弯强度为812±38MPa,断裂韧性为8.8±0.1MPa·m1/2;在1200℃、Ar气氛下,分别为560±61MPa和6.1±0.4MPam1/2.在氮气氛下,由于晶须的损伤易导致材料的力学性能下降.添加剂可降低复合材料的烧结温度,但不利于其力学性能.显微结构观察发现,不同温度下,AS复合材料的增韧机理有变化. 相似文献
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由SiO2/3Y-TZP包裹复合粉体制备ZrSiO4/3Y-TZP细晶陶瓷 总被引:1,自引:0,他引:1
对湿化学法制备的SiO2/3Y-TZP包裹复合粉体进行了热压烧结研究,并利用X射线衍射和透射电镜表征了烧结体的物相和显微结构.在低于1300℃,复合粉体发生瞬时粘性烧结,材料密度迅速提高;随着烧结温度的升高,SIO2和ZrO2发生反应生成ZrSiO4.在1500℃热压条件下,制备了平均晶粒尺寸为350nm的ZrSiO4/3Y-TZP细晶复相材料.我们认为,在烧结过程中形成的第二相ZrSiO4,特别是SiO2包裹层对抑制基体晶粒长大起主要作用. 相似文献
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碳纤维增强TiC复合材料的制备与高温强度 总被引:4,自引:0,他引:4
采用热压烧结工艺制备了碳纤维增强 Ti C复合材料 (2 0 vol%碳纤维 ) ,研究了热压烧结温度对力学性能的影响和碳纤维对复合材料高温强度的增强作用。结果表明 :采用球磨湿混工艺将易于团聚的短碳纤维均匀地分散在 Ti C基体中 ,Cf/ Ti C复合材料最佳热压烧结温度为 2 10 0℃ ,Cf/ Ti C复合材料的室温抗弯强度为 5 93MPa,断裂韧性为 6 .87MPa· m1 / 2 ,140 0℃时的高温抗弯强度为 439MPa。定量分析了碳纤维对复合材料的增强和增韧效果 相似文献
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以Ti、Al和活性炭粉为原料,通过高能球磨及热压反应烧结法在1200℃合成Al2O3/Ti2AlC复合材料,即是在Ti2AlC层状材料的制备过程中同时被合成。研究了烧结温度对反应产物的影响,并重点分析了材料微观结构和性能的关系。结果表明:高能球磨使Ti2AlC的烧结温度降低,热压烧结在1200℃时得到了物相比较均匀、致密的Al2O3/Ti2AlC复合材料;同时分析材料微观结构,少量Al2O3的引入抑制了Ti2A1C晶体的异常长大,使得晶粒细小且均匀。力学性能测试表明,该材料室温抗弯强度可达275.4MPa,断裂韧度可达10.5MPa.m1/2,密度为4.2g/cm3。 相似文献
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放电等离子超快速烧结氧化铝力学性能和显微结构研究 总被引:2,自引:0,他引:2
本文介绍用放电等离子超快速烧结方法制备的氧化铝陶瓷的力学性能和显微结构特征.超快速烧结的升温速率为600℃/min,在烧结温度不保温,迅即在3min内冷却至600℃以下.与保温时间为2h的无压烧结相比,可降低烧结温度和提高样品密度.力学性能研究结果表明,用放电等离子超快速烧结方法制备的纯氧化铝陶瓷的抗弯强度高达800MPa以上,比通常氧化铝陶瓷的抗弯强度高出一倍.用SEM研究了在不同温度下超快速烧结的纯氧化铝陶瓷的显微结构特征. 相似文献
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Standards are the basis for production enterprises to organize production ex-factory inspection trade 《中国标准化(英文版)》2008,25(1):24-25
Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.…… 相似文献
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Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß. 相似文献
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《中国标准化(英文版)》2014,(4)
正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from 相似文献
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《中国标准化(英文版)》2014,(5)
正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively. 相似文献
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《中国标准化(英文版)》2014,(4)
正China and Greece Sign the Standardization Cooperation Agreement Witnessed by Chinese Premier Li Keqiang and Greek Prime Minister Antonis Samaras,AQSIQ Minister Zhi Shuping and ELOT Chairman and Executive Director Angelos Tolkas signed the SAC-ELOT Standardization Cooperation Agreement.The Agreement is one of the critical cooperation documents signed during Li Keqiang’s visit in Greece,encouraging China and Greece to 相似文献
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刘智洋 《中国标准化(英文版)》2014,(4):M0002-M0002
正The Chinese Premier Li Keqiang's recent trip to the UK has reinforced the China-UK comprehensive strategic partnership;just as the British Prime Minister David Cameron put it,"the relationship is gaining in strength,depth and understanding"after a bucket of business deals being inked worth more than 30 billion US dollars.From the first agreement signing in 2004 to the new agreement of mutual standards recognition and adoption in 相似文献
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《中国标准化(英文版)》2014,(4):3-3
正A national directory of standards complexes for strategic emerging sectors was recently developed and released jointly by 12governmental departments,namely,SAC,NDRC,MOST,MIIT,MEP,MOA,AQSIQ,State Forest Administration,State Administration of Science and Technology for National Defense,State Oceanic Administration and National Railway Administration. 相似文献
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《中国标准化(英文版)》2014,(4)
正Four new national standards on air pollutant emission control offi cially issued by the Ministry of Environment Protection(MEP)together with AQSIQ and SAC has been brought into force from July 1,2014.The Emission standard for air pollutants of coal-burning,oil-burning and gasfi red boilers,which is the strictest emission standard historically,will tackle the stubborn pollution problem of boilers and waste incineration in most of China’s regions. 相似文献
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《新型炭材料》2014,(6):460
New Carbon Materials is a bimonthly journal published with the permission of the Ministry of Science and Technology and of the State News and Publication Agency.The journal is sponsored by the Institute of Coal Chemistry,Chinese Academy of Sciences,and is published by Science Press.Aims and Scope 相似文献
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《中国标准化(英文版)》2014,(5):3-3
正Recently,National Copyright Administration of China(NCAC)has rewarded 215 organizations and 179 individuals for their outstanding efforts on investigating standards copyright infringement and piracy in 2013.Hua Jianhua,the Deputy-Director of National Standards Copyright Protection Workgroup Office won a third prize of the national individual award.In 2012,SAC set up the national standards copyright protection working group,and developed policies to crack down standards infringement and piracy behaviors and to strengthen standards copyright protection. 相似文献