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Wear Behavior of Functionalized Multi-walled Carbon Nanotube Reinforced Epoxy Matrix Composites
Sulong, Abu Bakar,Park, Joohyuk,Lee, Naesung,Goak, Jeungchoon Sage Publications 2006 Journal of composite materials Vol.40 No.21
<P>This article studies the tribological behavior of functionalized multi-walled carbon nanotubes (MWNTs) reinforced epoxy matrix composites. MWNTs reinforced epoxy composites are fabricated by an injection molding process. The effects on the tribological properties of different loading concentrations and different functional groups of MWNTs are investigated by using a linear reciprocal wear tester. As increasing the concentration of MWNTs reduces wear loss, better tribological property was attained on functionalized MWNTs than as-produced MWNTs. The changes in worn surface morphology are observed in order to investigate the wear behavior. The MWNTs in the epoxy matrix near the surface are exposed and became a lubricating working film on the worn surface. The dispersion and interfacial bonding of MWNTs in the epoxy matrix are investigated from the fracture surface. The existence of MWNT at the wear surface is verified by a Raman spectrometer.</P>
표면 개질화된 탄소나노튜드 강화 고분자 복합재료의 마로 특성
아부바카 술롱(Abu Bakar Sulong),박주혁(Joohyuk Park) 한국트라이볼로지학회 2005 한국윤활학회지(윤활학회지) Vol.21 No.6
Various carbon nanotubes (CNTs) are added into the epoxy matrix as reinforcements to investigate the effect on the wear behavior. Effects to the tribological properties of different loading concentrations and types of surface modification are investigated by using a linear reciprocal wear tester. As increasing the concentration of CNTs shows the reduction of the wear loss. Moreover, surface modified CNTs give better tribological property than as produced CNTs. It is due that the functional groups on the surface of CNTs increase the interfacial bonding between CNTs and epoxy matrix through chemical bonding. Changes in worn surface morphology are observed by optical microscope and SEM to investigate the wear behavior. CNTs in the epoxy matrix near the surface are exposed and it becomes the lubricating working film on the worn surface. It reduces the friction and results in the lower surface roughness morphology in the epoxy matrix as increasing the contents of the CNTs.
Electrical Conductivity Behavior of Chemically Surface Modified MWNTs in Epoxy Matrix Composites
Joohyuk Park,Abu Bakar Bin Sulong 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.6
Few attempt to study the effects of chemical surface modification carbon nanotubes (CNTs) to the electrical conductivity nanocomposites instead to increase dispersion and interfacial bonding strength between CNTs and polymer matrix. Therefore, the electrical conductivity of two type’s chemical surface modified (carboxylated and octadecylated) multi-walled carbon nanotubes (MWNTs), non ionic surfactant additive MWNTs and as produced MWNTs reinforced epoxy nanocomposites are investigated by as function of MWNTs concentration. As-produced MWNTs and surfactant additive MWNTs nanocomposites resulted higher electrical conductivity at low loading concentration. However, chemically surface modified MWNTs significantly decreased the electrical conductivity of epoxy nanocomposite. Therefore, it can be deduced that the chemically surface modified MWNTs are not suitable electrical applications.
Process Parameters Used in Macro/Micro Powder Injection Molding: An Overview
Al Basir,Abu Bakar Sulong,Nashrah Hani Jamadon,Norhamidi Muhamad,Ukwueze Bonaventure Emeka 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.7
Powder injection molding (PIM) is a well-known manufacturing technique for the production of complex, net-shaped macroparts using a broad range of materials and alloys. Eventually, the PIM method has been modifed into micro-powder injectionmolding (μPIM) because of the increasing demand of micro-parts in global market. Now-a-days PIM and μPIM processesare extensively using to fabricate components for electronic, automobile, and biomedical felds. In this paper, the importantprocess parameters that had been used to fabricate defect-free macro and micro-sized parts of diferent metals, ceramics,and alloys using the above-mentioned techniques have been reviewed. This article is enclosed with a brief discussion onthe future research guidelines addressing diferent aspects related to the two-component macro and micro powder injectionmolding. This paper could be a worthy source for those investigators who aim to work on PIM and μPIM technology.
Study on the influence mechanism of sintering hydroxyapatite (HA)
Nabilah Afiqah Mohd Radzuan,Abu Bakar Sulong,Farhana Mohd Foudzi,Mohd Yusuf Zakaria,Mohd Ikram Ramli 한양대학교 세라믹연구소 2020 Journal of Ceramic Processing Research Vol.21 No.6
As one of promising biomaterial, hydroxyapatite (HA) is potentially used as an implant component. Yet, to date, HA stillencounter difficulties to be comerciallise due to the easily deteriorate and often fluctuate mechanical performance whichdepends on the manufacturing process. Thus, this study aims to experiment the influence of HA composition and sinteringparameter on the densification, morphological analysis and flexural strength in terms of green parts and sintered HA. The HAparts are fabricated through the powder injection moulding process with the pressure applied between 10 and 12 bar at 150 oC. The HA compositions are varied of 54 wt.%, 55 wt.% and 56 wt.% while the sintering parameter are set at 1,100 oC, 1,200 oCand 1,300 oC. The 56 wt.% of HA parts recorded the densification of 2.13 g/cm3 and 2.95 g/cm3 for both green parts andsintered parts at 1,300 oC. However, as the sintering temperature reduced to 1,200 oC, the densification reached the value of2.9 g/cm3 with the existence of porous structure to allow tissue growth. This finding suggested that the HA parts can be massproduce using powder injection moulding process at 1,200 oC, with a minimum existence of porosity to allow tissue growth inbetween the HA structure.