• Elastomers and Composites
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• v.58 no.4
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• pp.161-172
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• 2023

Because particulate matter has emerged as a major contributor to air pollution, the tire industry has conducted studies to reduce particulate matters from tires by improving tire performance. In this study, we compared the conventional blending method, in which rubber, filler, and additives are mixed simultaneously, to the Y-blending method, in which masterbatches are blended. We manufactured carbon black (CB)-filled natural rubber (NR)/butadiene rubber (BR) blend and silica-filled epoxidized NR/BR blend compounds to compare the effects of the two blending methods on the physical properties of the compounds and the amount of particulate matter generated. The Y-blending method provided uniform filler distribution in the heterogeneous rubber matrix, improved processability, and exhibited low rolling resistance. This method also improved physical properties owing to the excellent filler-rubber interaction. The results obtained from measuring the generation of particulate matter indicated that, the Y-blending method reduced PM_2.5 particulate matter generation from the CB-filled and silica-filled compounds by 38% and 60%, and that of PM₁₀ by 29% and 67%, respectively. This confirmed the excellence of the Y-blending method regarding the physical properties of truck bus radial tire tread compounds and reduced particulate matter generated.

• Journal of Korea Foundry Society
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• v.21 no.6
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• pp.311-321
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• 2001

• Proceedings of the Materials Research Society of Korea Conference
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• 1995.11a
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• pp.119-119
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• 1995

• Proceedings of the Korean Ceranic Society Conference
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• 2000.04a
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• pp.97.1-97.1
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• 2000

• Composites Research
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• v.17 no.6
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• pp.1-7
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• 2004

The studies of particulate reinforced composites have been conducted for many years. The nanocomposites to be studied vigorously in recent years are one of them. We fabricated and studied multi-walled carbon nanotube(MWNT)/epoxy composites which may be useful as matrix for continuous fiber-reinforced composites. We investigated tensile properties of MWNT/epoxy composites as a function of MWNT concentration, which were prepared by the fabrication method established in this study. Tensile stiffness and strength increased 19% at 0.5 wt% and 12% at 0.2 wt%, respectively. We observed the reaggregation phenomenon of MWNTS during curing, which should be controlled to obtain higher tensile properties.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.4
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• pp.174-181
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• 2005

In order to investigate the behavior of fatigue crack growth of SiC-particulate- reinforced Al-Si alloy composites, fatigue tests using single edge notched tension(SENT) specimens were performed. Composite materials were manufactured by using both permanent die casting and extrusion processes with different volume fractions of $10\%\;and\;20\%$. $SiC_p-reinfurced$ Al-Si composites showed the increased levels of threshold stress intensity factor range, ${\Delta}K_{th}$, for the increased volume fractions of SiC particles, which implies the increased fatigue crack growth resistance at the threshold or low ${\Delta}K$ levels, compared to the unreinforced Al-Si alloy. In the Paris region, however, the composites showed the increased rate of crack growth resulting in the unfavorable effects on the fatigue crack growth resistance. Critical stress intensity factor range at unstable crack growth leading to final fracture decreased as the volume fraction of SiC particle increased, because of the reduced fracture toughness of the composites. Extruded materials showed higher threshold and critical values than the cast materials.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.5
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• pp.449-460
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• 2014

Since the emergence of domestically produced automobiles in 1964, the number of automobiles in circulation in South Korea has increased constantly. With this rapidly increasing number of automobiles, automobile-induced environmental pollution has become an issue of great concern, especially with regard to air pollution. Of the carbon composites contained in automobile exhaust gas, PAHs are known to be carcinogenic and highly deleterious to humans and thus need to be urgently mitigated. To address this issue of PAHs, this study was conducted to estimate qualitative of particulate PAHs contained in carbon composites in automobile exhaust gas, by capturing all particulate matter discharged from the latter. To allow for differentiated analyses, the automobiles investigated were divided into 4 groups: gasoline vehicle, motocycle, diesel vehicle, and LPG vehicle. Samples were analyzed using two methods. First, in-depth analysis was performed on organic carbon (OC) and elemental carbon (EC) composites with analysis parameters, using the Thermal Optical Transmittance Method (NIOSH 5040). Second, for the examination of particulate PAHs, GC/MSD was used to analyze the 16 PAH species specified by the Environmental Protection Agency (EPA). The analyses yielded the findings that diesel vehicles had the highest mass concentration ($2,007{\mu}g/m^3$), followed by motocycle ($1,066{\mu}g/m^3$), LPG vehicle ($392{\mu}g/m^3$), and gasoline vehicles ($270{\mu}g/m^3$). The highest carbon concentrations in total particulate matter by vehicle weight were produced from LPG vehicle (79.8%), followed by gasoline vehicle (77.4%), motocycle (69.8%), and diesel vehicle (59.1%).

• Journal of the Korean Ceramic Society
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• v.50 no.6
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• pp.439-445
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• 2013

Both an unreinforced $Al_2O_3$/Al matrix and a ${\alpha}-Al_2O_3$ particulate reinforced composite have been produced by the oxidation of an Al surface doped with NaOH in the absence of any other dopant. Fabrication of the matrix was initiated by the formation of $NaAlO_2$, which provides a favorable surface structure for the matrix formation by breaking the protective $Al_2O_3$ layer on Al. During the matrix growth, the external surface of the growth front was covered with a very thin sodium-rich oxide. A cyclic formation process of the sodium-rich oxide on the growth surface was proposed for the sodium-induced directed metal oxidation process. This process involves dissolution of the sodium-rich oxide, motion of Na to the growth front, and re-formation of the oxide on the surface. Near-net-shape composites were fabricated by infiltrating an $Al_2O_3$/Al matrix into a ${\alpha}-Al_2O_3$ particulate preform, without growth barrier materials. The infiltration distance increased almost linearly in the NaOH-doped preform.

• Composites Research
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• v.13 no.4
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• pp.1-10
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• 2000

SiC particulate reinforced metal matrix composites(MMCs) are emerging as candidate materials for the automobile and aerospace industries due to their significant increase in elastic modulus and strength compared to conventional metallic materials. However, in order to make successful application of MMCs, it is very important to understand micro-failure mechanism under cyclic loading because failure mechanism of MMC is dominated by accumulation of micro-failure due to applied loading. In this study, ultrasonic Lamb wave and acoustic emission(AE) have been used to monitor microscopic damage accumulation under cyclic loading for SiC particulate reinforced metal matrix composite(SiCp/A356). It was found that the change in velocity and attenuation of ultrasonic Lamb wave due to the increase of loading cycles could be characterized by three different stages corresponding to the microscopic fracture processes. The characteristic of AE signal at each stage was analyzed and discussed by comparing with the change of ultrasonic characteristic in MMCs.

• Korean Journal of Materials Research
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• v.5 no.7
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• pp.765-774
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• 1995

The hot deformation behaviour of particulate reinforced aluminium 6061 Al composite were investigated by hot compression tests in the temperature range from 623K to 823K with strain rate of 10$^{-3}$ ~5.0 S$^{-1}$ . The effect of reinforced particulate volume fraction, mean diameter on the high temperature flow stress has also been studied. Experimental results showed that the increase in the volume fraction of reinforcement contributed to the rising of yield stress, but the stress above the yield point appeared to be steady state at all volume fractions. The apparent activation energy for deformation was 290KJ/mo1 for unreinforced 6061 Al, 327KJ/mo1 for 6061 Al-20vo1.% SiC composite and 531KJ/mo1 for 6061 Al-20vo1.%A1$_2$O$_3$composite. It appeared that $Al_2$O$_3$reinforced composites was more difficult to hot deform.