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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korean Society of Tribologists and Lubrication Engineers
Journal Basic Information
Journal DOI :
The Korean Society of Tribologists and Lubrication Engineers
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Volume & Issues
Volume 27, Issue 6 - Dec 2011
Volume 27, Issue 5 - Oct 2011
Volume 27, Issue 4 - Aug 2011
Volume 27, Issue 3 - Jun 2011
Volume 27, Issue 2 - Apr 2011
Volume 27, Issue 1 - Feb 2011
Selecting the target year
The Effect of Ball-milling Energy on Combustion Synthesis Coating of Cu-Al-Ni Based Intermetallics
Lee, Han-Young ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 27, issue 1, 2011, Pages 1~6
DOI : 10.9725/kstle.2011.27.1.001
The possibility of Cu-Al-Ni intermetallic coating on the mild steel through the combustion synthesis has been investigated. In particular, the effect of the ball milling energy on the microstructure of the coating layer was examined to obtain the best coating condition. Experimental results show that Cu-Al-Ni powder compact was explosively synthesized and successfully coated with the steel matrix. It was revealed that the formation of
intermetallic decreased with increase in the ball milling energy. This result supports that the high energy ball milling would be effective for obtaining the most suitable microstructure for Cu-Al-Ni coating layer. However, the excessive ball milling energy seems to decrease the bonding strength between the coating layer and the matrix.
A Study of the Effects of Pressure Velocity and Fluid Viscosity in Abrasive Machining Process
Yang, Woo-Yul ; Yang, Ji-Chul ; Sung, In-Ha ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 27, issue 1, 2011, Pages 7~12
DOI : 10.9725/kstle.2011.27.1.007
Interest in advanced machining process such as AJM(abrasive jet machining) and CMP(chemical-mechanical polishing) using micro/nano-sized abrasives has been on the increasing demand due to wide use of super alloys, composites, semiconductor and ceramics, which are difficult to or cannot be processed by traditional machining methods. In this paper, the effects of pressure, wafer moving velocity and fluid viscosity were investigated by 2-dimensional finite element analysis method considering slurry fluid flow. From the investigation, it could be found that the simulation results quite corresponded well to the Preston`s equation that describes pressure/velocity dependency on material removal. The result also revealed that the stress and corresponding material removal induced by the collision of particle may decrease under relatively high wafer moving speed due to the slurry flow resistance. In addition, the increase in slurry fluid viscosity causes the reduction of material removal rate. It should be noted that the viscosity effect can vary with the shape of abrasive particle.
The Improvement of Machining Accuracy and Compensation of Feeding Error in CNC Lathe Using Ultra Precision Fast Tool
Kim, Jae-Yeol ; Kwak, Nam-Su ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 27, issue 1, 2011, Pages 13~18
DOI : 10.9725/kstle.2011.27.1.013
The ultra-precision products which recently experienced high in demands had included the large areas of most updated technologies, for example, the semiconductor, the computer, the aerospace, the media information, the precision machining. For early 21st century, it was expected that the ultra-precision technologies would be distributed more throughout the market and required securing more nation-wise advancements. Furthermore, there seemed to be increasing in demand of the single crystal diamond tool which was capable of the ultra-precision machining for parts requiring a high degree of complicated details which were more than just simple wrapping and policing. Moreover, the highest degree of precision is currently at 50 nm for some precision parts but not in all. The machining system and technology should be at very high performed level in order to accomplish this degree of the ultra-precision.
Application of Flexible-Type Sintered Brake Pads
Kim, Soung-Kwon ; Kim, Sang-Ho ; Kwon, Seok-Jin ; Lee, Hi-Sung ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 27, issue 1, 2011, Pages 19~24
DOI : 10.9725/kstle.2011.27.1.019
Metallic sintered brake pads are often applied to mid/high speed train due to their high strength and thermal characteristics. Imbalance contact between discs and pads can greatly influence the life span, one sided wear, discs attack/crack and threat the safety of the train during operation. In this research, we analyzed pressure/temperature distribution between brake pads and disks. Analyzed data had been verified and modified to conduct further tests of flexible brake pads with small/full-scale dynamo test. Flexible brake pads were installed to high speed train to conduct further tests to identify the differences between rigid brake pads and flexible brake pads. In result, Flexible brake pads showed outstanding disk thermal stability, one sided wear, noise and wear rate than rigid brake pad.
Evaluation of Friction Torque for a Turbopump Ball Bearing
Jeon, Seong-Min ; Kwak, Hyun-Duck ; Kim, Jin-Han ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 27, issue 1, 2011, Pages 25~33
DOI : 10.9725/kstle.2011.27.1.025
Rolling contact ball bearings are utilized almost exclusively for liquid propellant rocket engine turbopump. Turbopump ball bearings are required to endure high speed and high load for a poor lubricated condition in cryogenic environment. To evaluate bearing heat generation performance, friction torque is investigated as a function of rotation speed, bearing load and cooling flow rate through an experimental study using water coolants. Radial and axial loads are simultaneously applied to the test bearing by gas pressurized cylinder rod. Endurance performance of bearing has been also verified under the bearing required load for operating condition during total accumulated test time 2,100 sec.
Effects of Abrasive Size and Impact Angle on the Contact Stress in Abrasive Machining Process
Kwak, Haslomi ; Kim, Wook-Bae ; Sung, In-Ha ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 27, issue 1, 2011, Pages 34~39
DOI : 10.9725/kstle.2011.27.1.034
In this study, finite element analysis of particle-surface collision using 2-dimensional elements was performed to observe the effects of abrasive size and impact angle. The result of the simulation on the change in abrasive size revealed that larger abrasive particle induced larger contact stress due to force transfer through slurry fluid as the particle moved and pushed the fluid. This observation brought an important finding that the slurry fluid could make the workpiece surface soften and then change the mechanical properties of the surface layer such as elastic modulus and yield strength. As for the impact angle, it was found that the contact stress increased with the angle of impact and jumped up at a specific angle. Such result would be attributed to the complex effects of the impact velocity and angle.
A Study for Influences of Supplied Lubricant Quantities on Pitting Life of Spur Gears
Joo, Jin-Wook ; Moon, Seok-Man ; Kim, Tae-Wan ; Cho, Yong-Joo ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 27, issue 1, 2011, Pages 40~44
DOI : 10.9725/kstle.2011.27.1.040
The object of this study is to investigate influences of supplied lubricant quantities on spur gear`s pitting life. Pitting is a sort of contact fatigue failures and made by a repetitive load. Basically, pitting is difficult to predict its life by an analysis due to many factors to be considered about tribology problems. In this paper, pitting life was proved by experiment using two roller machine. For a contact fatigue test, operating circumstances should be considered. During the test, temperature and lubricant quantities are considered and to investigate an influence of lubricant quantities, a comparison between optimally enough and not enough lubricant quantity was implemented.