• Journal of the Korean Society for Precision Engineering
• /
• v.32 no.11
• /
• pp.983-988
• /
• 2015

This paper details a new ultra-precise turning method for increasing surface quality, "Multi Point B Axis Control Method." Machined surface error is minimized by the compensation machining process, but the process leaves residual chip marks and surface roughness. This phenomenon is unavoidable in the diamond turning process using existing machining methods. However, Multi Point B axis control uses a small angle (< $1^{\circ}$) for the unused diamond edge for generation of ultra-fine surfaces; no machining chipping occurs. It is achieved by compensated surface profiling via alignment of the tool radial center on the center of the B axis rotation table. Experimental results show that a diamond turned surface using the Multi Point B axis control method achieved P-V $0.1{\mu}m$ and Ra 1.1nm and these ultra-fine surface qualities are reproducible.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2008.11a
• /
• pp.345-346
• /
• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.06a
• /
• pp.469-470
• /
• 2009

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.10 no.2
• /
• pp.1-8
• /
• 2011

5-axis NC machining has a good advantage of the accessibility of tool motion by adding two rotary axes. It offers numerous advantages such as expanding machining fields in parts of turbo machineries like impeller, propeller, turbine blade and rotor, reasonable tool employment and great reduction of the set-up process. However, as adding two rotary axes, it is difficult to choose suitable machining conditions in terms of cutter path and cutter posture at a cutter contact point. Therefore in this paper, it is proposed to decide suitable machining condition through an experimental method such as adopting various cutter paths, cutter postures types. Also, in order to increase the efficiency of 5-axis machining, it is necessary to minimize the cutter posture changes and create a continuous cutter path while avoiding interference. This study, by using an MC-space algorithm for interference avoidance and an MB-spline algorithm for continuous control, is intended to create a 5-axis machining cutter path with excellent surface quality and economic feasibility. finally, this study will verify the effectiveness of the suggested method through verification processing.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2013.05a
• /
• pp.127-128
• /
• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.10a
• /
• pp.101-102
• /
• 2006

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.10a
• /
• pp.543-544
• /
• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2013.05a
• /
• pp.537-538
• /
• 2013

• Progress in Superconductivity and Cryogenics
• /
• v.19 no.2
• /
• pp.9-13
• /
• 2017

This study presents a simple method to control the seed orientation which leads to the various growth characteristics of a single grain REBCO (RE: rare-earth elements) bulk superconductors. Seed orientation was varied systematically from c-axis to a-axis with every 30 degree rotation around b-axis. Orientations of a REBCO single grain was successfully controlled by placing the seed with various angles on the prismatic indent prepared on the surface of REBCO powder compacts. Growth pattern was changed from cubic to rectangular when the seed orientation normal to compact surface was varied from c-axis to a-axis. Macroscopic shape change has been explained by the variation of the wetting angle of un-reacted melt depending on the interface energy between $YBa_2Cu_3O_{7-y}$ (Y123) grain and melt. Higher magnetic levitation force was obtained for the specimen prepared using tilted seed with an angle of 30 degree rotation around b-axis.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.11a
• /
• pp.157-158
• /
• 2010