http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Hardness of Multi Wall Carbon Nanotubes reinforced aluminium matrix composites
Bradbury, C.R.,Gomon, J.K.,Kollo, L.,Kwon, H.,Leparoux, M. Elsevier Sequoia 2014 JOURNAL OF ALLOYS AND COMPOUNDS Vol.585 No.-
The macro hardness (HV<SUB>20</SUB>) was measured for aluminium and 1-9wt% Multi Wall Carbon Nanotubes (MW-CNTs) composites that were milled and hot compressed. The hardness increased with increasing fraction of MW-CNTs up to 6wt% (HV<SUB>20</SUB>=151) and then remained constant. The content of MW-CNTs was significantly higher than reported for similar materials and measurements. The composites were analysed by Raman, TEM and XRD. The Raman and TEM showed MW-CNTs were still present after milling and hot pressing. The XRD was used to determine the Al crystallite size which was used to determine Hall-Petch contribution to the composite hardness.
Sintering and Microstructure Characteristics of 42CrMo4 Steel Processed by Spark Plasma Sintering
Ridvan Yamanoglu,William Bradbury,Eugene A. Olevsky,Randall M. German 대한금속·재료학회 2013 METALS AND MATERIALS International Vol.19 No.5
Rapidly solidified micron sized 42CrMo4 steel powder with a size range of 150-250 μm produced by plasma rotating electrode process was consolidated using a recently developed spark plasma sintering (SPS) process. The relationship between sintering parameters (temperature and soaking time) and microstructural properties was investigated. The effect of slow and high heating regimes on the consolidation of sintered compacts has been also investigated. Maximum relative density (99.2%) was obtained at 1000 °C, under 50 MPa pressure, with 8 min holding time and 200 °C/min heating rate. The microstructure of sintered steel was influenced by carburization occuring inside the graphite SPS process die. The diffusion of carbon produced martensite structure near the surface region and hardened the surface. This effect was investigated in detail using optical microscopy and hardness measurement. Scanning electrone microscopy was also used to examine the fracture surface of sintered compacts. High heating rate promoted the relative density at low temperature compared to high temperature.
Suteewong, Teeraporn,Sai, Hiroaki,Lee, Jinwoo,Bradbury, Michelle,Hyeon, Taeghwan,Gruner, Sol M.,Wiesner, Ulrich Royal Society of Chemistry 2010 Journal of materials chemistry Vol.20 No.36
<P>This work reports on the structural evolution during room temperature synthesis of hexagonally ordered mesoporous silica nanoparticles with and without embedded iron oxide particles. Oleic acid-capped iron oxide nanoparticles are synthesized and transferred to an aqueous phase using the cationic surfactant, hexadecyltrimethylammonium bromide (CTAB). MCM-41 type silica and composite nanoparticles are fabricated <I>via</I> sol–gel synthesis. Aliquots are taken from the solution during synthesis to capture the particle formation process. Transmission Electron Microscopy (TEM) and Small Angle X-ray Scattering (SAXS) reveal a transition from a disordered to an ordered structure in both synthesis systems. Along with the evolution of structure, iron oxide nanoparticles acting as seeds at the early stages are relocated from the particle centers to the edges. Nitrogen sorption measurements for iron oxide-embedded mesoporous nanoparticles indicate surface areas as high as for the mesoporous silica nanoparticles without iron oxide.</P> <P>Graphic Abstract</P><P>We report on the structural evolution during synthesis of ordered mesoporous silica nanoparticles with and without embedded magnetic nanoparticles. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c0jm01002b'> </P>