激光参数对碳纤维复合材料质量烧蚀率的影响

为了研究激光参数对碳纤维增强有机硅改性环氧树脂复合材料质量烧蚀率的影响规律, 选用不同激光参数、采用高强度CO₂激光器对该复合材料进行了激光辐照试验。分别分析了入射激光的辐照时间、强度和光斑直径对碳纤维增强有机硅改性环氧树脂复合材料质量烧蚀率的影响规律。研究结果表明: 激光辐照时间对该复合材料的质量烧蚀率的影响不大, 而该复合材料的质量烧蚀率随入射激光强度和光斑直径的增大而增大。      

硅溶胶改性处理对碳纤维/环氧树脂复合材料拉伸性能的影响

用溶胶-凝胶法制备硅溶胶对碳纤维进行表面改性,观测了环氧树脂液滴在单向排列碳纤维集束表面的铺展过程;以环氧树脂为基体制备单向排列的碳纤维/环氧树脂复合材料,研究了硅溶胶改性处理碳纤维对其拉伸性能的影响。结果表明:碳纤维经过硅溶胶改性处理后,Si—o—Si,-NH₂等极性官能团的引入改善了环氧树脂对其的浸润性能,从而改善了碳纤维与环氧树脂间的界面粘结性能,使碳纤维/环氧树脂复合材料的横向拉伸强度显著改善,但纵向拉伸强度影响不大;与未经过表面处理的复合材料相比,经过硅溶胶改性处理的碳纤维/环氧树脂复合材料其横向拉伸强度提高了62.74%;与用硝酸处理的碳纤维制备的复合材料相比,用硝酸处理后再用硅溶胶处理的碳纤维所制备的复合材料,其横向拉伸强度提高了35.27%。     

紫外光辐射固化共混改性环氧树脂复合材料的力学和热老化性能

利用湿法手工铺叠工艺和紫外光固化技术,制备以双酚A环氧树脂E-44与有机硅环氧树脂ES-06共混改性光敏树脂体系为基体的玻璃布增强复合材料,测试并分析比较了复合材料的力学和热老化性能.结果表明,在光敏树脂基体中加入链转移剂以及对光固化后的复合材料进行加压后固化处理,均能显著提高复合材料的性能.采用E-44与ES-06质量比为2:1的共混改性树脂体系制备的复合材料的力学性能和耐热老化性能最佳,其拉伸强度达到146.6 MPa,拉伸模量为19.4GPa,弯曲强度为152.5MPa,层间剪切强度达到16.2 MPa.     

碳纤维复合材料热防护涂层的研究

以环氧改性有机硅树脂为基料,配以金属氧化物和硅酸盐类填料,制备了可用于碳纤维复合材料的耐高温抗烧蚀涂层。该热防护涂层导热系数为0.235W/(m·℃),氧-乙炔线烧蚀率为0.278mm/s,质量烧蚀率为0.0758g/s,附着力良好,且具有优良的隔热性能。     

碳纤维改性环氧树脂基复合材料的制备及性能研究

以环氧树脂E51为基础材料,碳纤维为增强材料,制备出了不同碳纤维掺杂量(0,3%,6%,9%(质量分数))的改性环氧树脂基复合材料,研究了碳纤维掺杂量对环氧树脂基复合材料力学性能、微观形貌、热稳定性和导热性能的影响。结果表明,适量碳纤维的掺杂提高了环氧树脂基复合材料的力学性能、热稳定性和导热性能。随着碳纤维掺杂量的增加,改性环氧树脂基复合材料的拉伸强度、断裂延伸率、弯曲强度和弯曲模量均先增大后降低,当碳纤维的掺杂量为6%时,复合材料的拉伸强度、断裂延伸率、弯曲强度和弯曲模量均达到了最大值,分别为48.5 MPa, 1.86%,85.6 MPa和3.09 GPa。随着碳纤维掺杂量的增加,复合材料的分解温度和残留量先升高后降低,当碳纤维的掺杂量为6%时,复合材料的分解温度和残留量达到最大,分别为453.7℃和4.9%。复合材料的导热系数随碳纤维掺杂量的增加而增大,当碳纤维的掺杂量<6%时,导热系数增长速率较快。综合分析可知,碳纤维的最佳掺杂量为6%。     

ZrB2-SiC复相陶瓷涂层制备及其保护C/C-SiC复合材料性能

为提高C/C-SiC复合材料的超高温抗烧蚀性能,通过浆料涂刷和高温烧结相结合的方法在C/C-SiC复合材料表面制备了ZrB₂-SiC复相陶瓷涂层,利用EDS、SEM对涂层的成分及微观形貌进行了分析。对涂层材料的力学性能和抗烧蚀性能进行了表征,结果表明：制备的ZrB₂-SiC复相陶瓷涂层保护C/C-SiC复合材料的拉伸强度、弯曲强度及剪切强度分别为147 MPa、355 MPa和21.9 MPa,与无涂层保护的针刺C/C-SiC复合材料的力学性能相比略有下降。涂层材料具有良好的抗氧化烧蚀性能,经过热流密度为3 200 kW/m²的氧乙炔火焰烧蚀600 s试验,其线烧蚀率和质量烧蚀率分别为0.001 mm/s和0.0006 g/s。     

碳纤维-Ni/尼龙66复合材料的制备与性能表征

为制备低电阻率的尼龙66基复合材料,以碳纤维和镍粉(Ni)填充尼龙66制备碳纤维-Ni/尼龙66高导电复合材料。研究填料表面改性和含量对碳纤维-Ni/尼龙66复合材料导电性能和力学性能的影响。结果表明:KH550改性碳纤维和Ni有助于降低碳纤维-Ni/尼龙66复合材料的电阻率。碳纤维-Ni/尼龙66复合材料的电阻率随着碳纤维和Ni含量的增加而减小,且碳纤维和Ni填充尼龙66的导电逾渗阈值均为20wt%,此时制备的碳纤维-Ni/尼龙66复合材料的电阻率为455Ω·cm,熔融温度为202.2℃。碳纤维-Ni/尼龙66复合材料的弯曲强度和拉伸强度随着碳纤维或Ni含量的增加而先增大后减小。当Ni含量为20wt%时,碳纤维-Ni/尼龙66复合材料的弯曲强度和拉伸强度在碳纤维含量分别为20wt%和10wt%时达到最大值,分别为98MPa和70 MPa;当碳纤维含量为20wt%时,碳纤维-Ni/尼龙66复合材料的弯曲强度和拉伸强度则在Ni含量为30wt%和20wt%时达到最大值,分别为120 MPa和67 MPa。     

单宁酸协同改性超高分子量聚乙烯纤维与环氧树脂复合材料

将单宁酸共混改性的环氧树脂与单宁酸-金属Na~+络合改性超高分子量聚乙烯(UHMWPE)纤维进行复合,从而改善了UHMWPE纤维与环氧树脂的界面强度,提高了纤维增强复合材料的整体性能。改性后纤维表面的单宁酸与树脂基体中的单宁酸在界面处形成"桥联"作用。单宁酸共混改性环氧树脂是为了在环氧树脂中引入羟基以增强其力学强度。结果表明,当单宁酸在环氧树脂中的负载量为1%时,树脂基体的拉伸强度、弯曲强度达到最大值,分别为55.41 MPa, 74.24 MPa,与纯环氧树脂相比分别提高了67.5%和63.5%。同时界面剪切强度达到2.22 MPa,与原复合材料相比提高了64.8%。纵向纤维束使环氧树脂复合材料的拉伸强度增加到89.52 MPa,弯曲强度达到118.82 MPa,与纯复合材料相比,分别提高了120.2%,47.3%。通过扫描电镜图分析可以得出,纤维增强复合材料的破坏方式为黏接剂破坏。     

碳纤维丝束结构对碳纤维/酚醛复合材料烧蚀性能的影响EI北大核心CSCD

以酚醛树脂为基体,以平纹碳布和短切碳纤维两种结构形式的碳纤维为增强剂,制备碳纤维增强的碳/酚醛复合材料。采用氧/乙炔烧蚀实验对复合材料的耐烧蚀性能进行了对比性研究,采用电子拉力试验机对复合材料的弯曲性能进行表征,采用扫描电镜对复合材料烧蚀形面进行观察,并通过固体火箭发动机对复合材料的烧蚀性能进行考核验证。研究结果表明:以这两种结构形式的碳纤维为增强剂制备的碳/酚醛复合材料,其氧乙炔质量烧蚀率的大小与碳纤维丝束的大小具有正相关的特性,碳纤维丝束越小碳纤维质量烧蚀率越低,当碳纤维增强剂处于单丝状态时,复合材料的氧乙炔质量烧蚀率达到最低为0.046 g/s,并且碳纤维的型号规格对复合材料氧乙炔质量烧蚀率的影响变小。固体火箭发动机实验表明,单丝状态下的碳纤维/酚醛复合材料的抗烧蚀冲刷性能明显优于束状碳纤维/酚醛复合材料。     

SiC粒子改性聚氨酯/环氧树脂复合材料性能研究

利用聚氨酯预聚体对环氧树脂(EP)进行改性制备聚氨酯/环氧树脂复合材料,再加入碳化硅(SiC)粒子作为无机填料对复合材料改性。结果表明:改性后的复合材料力学、耐磨、防腐等性能均得到了提高,当SiC粒子的加入量为复合材料的6%时,复合材料的冲击强度为24.28kJ/m2,拉伸强度为66.19MPa,均达到最大值,磨损量为0.083g,提高了耐磨性能,耐酸碱腐蚀性能达到最佳。     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Optimum-Simulation von Ernteprozessen

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.     

Brainstorming for ISO Strategy 2016-2020

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     

CNAS Passes APLAC's PTP Review

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.     

新闻(英文)

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     

Win-Win Cooperation

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     

Systematic Approach for Emerging Industry

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.     

Strictest Pollutants Emission Standards

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.     

Instructions to Authors

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     

Progress on Standards Copyright Protection

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.