• Journal of Welding and Joining
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• v.23 no.6
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• pp.72-76
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• 2005

Friction surfacing of STS304 consumable rod on S45C substrate was investigated by microstructural observation and mechanical tests. STS304 layer formed a strongly-bonded thick layer under a wide range of surfacing conditions. The highest coating eefficiency was obtained in the condition of 1000rpm-2.5mm/sec-2.5mm/sec. The hardness distribution showed the peak value in the boundary layer and as the consumable rotation speed increased, the boundary layer also hardness increasing. As the consumable rotation speed and the traveling speed increased, the coating efficiency tended to decrease. On the other hand, as the feeding speed increased, the coating efficiency appeared to be increased. The new Fe-Cr-Ni alloy layer is showed in the interface layer on $5\~15{\mu}m$ width. After friction surfacing, corrosion resistance of STS 304 surfacing layers were equaled to that of STS304 consumable rod.

• International Journal of Highway Engineering
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• v.17 no.1
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• pp.17-24
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• 2015

PURPOSES : Recently, crack, rutting, and stripping problems from the surface of asphalt pavements in National highway are observed and they affect the drivers to feel uncomfortable on the road. Surface treatments are recommended to use in distressed pavements due to cost-effective, and improvement of surface performance. The purpose of this study is to evaluate the performance of micro-surfacing and polymer slurry seal treatments for distressed asphalt pavements. METHODS : Surface conditions and friction resistance are evaluated for asphalt pavements treated with micro-surfacing and polymer slurry seal mixes in National highway 30 line and 34 line. Visual observation is conducted and surface performance is measured by PES (Performance Evaluation Surveyor) in terms of crack ratio, rutting and IRI(International Roughness Index). BPN(British Pendulum Number) is measured by BPT(British Pendulum Tester) to evaluate the friction resistance in the field. RESULTS : The surface evaluation results are presented for asphalt pavement treated with micro-surfacing and polymer slurry seal treatments in National highway 30 line and 34 line. Based on the visual observation, micro-surfacing and polymer slurry seal treatments show better improvements in terms of cracks and stripping. Based on the surface conditions measured by PES vehicle, the surface performance of micro-surfacing treatments improves from 53.3% to 54.2% and the surface performance of polymer slurry seal treatments improves from 21.6% to 59.7%. However, the friction resistance of both micro-surfacing and polymer slurry seal treatments decreases from 2.5% to 6.7%. Further, it should be verified to produce the surface exposed with aggregates during the construction process of both treatment methods in the field. CONCLUSIONS : Based on the performance evaluation results in the filed, the surface performance of asphalt pavement treated with micro-surfacing and polymer slurry seal treatments improves from 21.6% to 59.7%. While, the friction resistance of asphalt pavement treated with micro-surfacing and polymer slurry seal treatments does not improve. It can be concluded that current micro-surfacing and polymer slurry seal treatments would improve surface performance but would not improve the friction resistance.

• Proceedings of the KWS Conference
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• 2005.06a
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• pp.229-231
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• 2005

Friction surfacing of STS304 consumable rod on S45C substrate was investigated by microstructural observation and mechanical tests. STS304 layer formed a strongly-bonded thick layer under a wide range of surfacing conditions. The hardness distribution showed the peak value in the boundry layer, while the highest coating efficiency obtained in the condition of 1000rpm-2.5mm/sec-2.5mm/sec. As the consumable rotation rate and the traveling rate increased, the coating efficiency tended to decrease. On the other hand, as the feeding rate increased, the coating efficiency appeared to be increased.

• Proceedings of the KWS Conference
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• 2005.11a
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• pp.132-134
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• 2005

The friction surfacing system which has been successfully developed in RIST has both position control and force control by using hydraulic cylinder. In friction surfacing process mechtrode rotation speed(N) and feeding speed($V_{z}$), travelling speed($V_{x,y}$) are of critical importance for the width and thickness of the coating. As a result of DOE with developed system, the main effect of coating thickness is a rotation speed of mechtrode.

• Journal of Welding and Joining
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• v.24 no.1
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• pp.43-49
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• 2006

This paper describes the friction surface modification which has been successfully developed with the friction stir welding recently There are several problems including just position control and backlash in conventional friction surface modification system. Therefore it has been developed the friction surface modification system which has been controlled precisely both position and force by driving hydraulic cylinder in this paper. The mechtrode rotation speed(N) and feeding speed(Vz), travel speed(Vx,y) are of critical importance for the width and thickness of the coating in friction surfacing process. But there is no theoretical method of determining interrelations between process parameters affect the coating width and thickness. As a result of DOE(design of experiment) with developed system, the coating thickness and width seemed to decrease according to increase the mechtrode rotation speed(N) and traveling speed(Vx,y), to decrease feeding speed(Vz) apparently. However as the result of regression analysis the main effect was only the mechtrode rotation speed in the coating thickness.