Browse Topic: Turning

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Application of Grey Relational Analysis in High-Speed Machining of Hardened AISI D6 Steel17-227-7-156607/01/2013
This study reports an optimization of finish turning of hardened AISI D6 (60 HRC) cold work tool steel with ceramic and cubic boron nitride cutting tools using grey relational analysis. Optimization of the process parameters was performed using quality characteristics, i.e., tool wear, surface roughness, machining force and specific cutting force. Analysis of variance was used for observing the most influencing machining parameters on the quality characteristics. Evaluation of tool wear type and wear mechanism was done by tool makers' microscope and scanning electron microscope analysis. The optimal process parameters were calculated using grey relation grade and confirmation test was performed. Based on analysis of variance results, the feed rate is the most significant controllable machining factor for the finish hard turning of AISI D6 according to the quality characteristics. Flank and crater wears were the prominent wear types on the ceramic and cubic boron nitride inserts. Grey
Kacal, Alaattin, Yildirim, Ferhat
Journal Article
Phase Retrieval System for Assessing Diamond Turning and Optical Surface DefectsTBMG-1055107/01/2011
An optical design is presented for a measurement system used to assess the impact of surface errors originating from diamond turning artifacts. Diamond turning artifacts are common by-products of optical surface shaping using the diamond turning process (a diamond-tipped cutting tool used in a lathe configuration).
Magazine Article
Pre-Finishing of SiC for Optical ApplicationsTBMG-987905/01/2011
A method is based on two unique processing steps that are both based on deterministic machining processes using a single-point diamond turning (SPDT) machine. In the first step, a high-MRR (material removal rate) process is used to machine the part within several microns of the final geometry. In the second step, a low-MRR process is used to machine the part to near optical quality using a novel ductile regime machining (DRM) process.
Magazine Article
Single-Mode WGM Resonators Fabricated by Diamond TurningTBMG-279905/01/2008
A diamond turning process has made possible a significant advance in the art of whispering-gallery- mode (WGM) optical resonators. By use of this process, it is possible to fashion crystalline materials into WGM resonators that have ultrahigh resonance quality factors (high Q values), are compact (ranging in size from millimeters down to tens of microns), and support single electromagnetic modes.
Magazine Article
Fabrication of Submillimeter Axisymmetric Optical ComponentsTBMG-TB-01162005/01/2007
Surfaces of components can be arbitrarily shaped to optimize spectral responses. NASA’s Jet Propulsion Laboratory, Pasadena, California It is now possible to fashion transparent crystalline materials into axisymmetric optical components having diameters ranging from hundreds down to tens of micrometers, whereas previously, the smallest attainable diameter was 500 μm. A major step in the fabrication process that makes this possible can be characterized as diamond turning or computer numerically controlled machining on an ultrahigh-precision lathe. This process affords the flexibility to make arbitrary axisymmetric shapes that have various degrees of complexity: examples include a flat disk or a torus supported by a cylinder (see figure), or multiple closely axially spaced disks or tori supported by a cylinder. Such optical components are intended mainly for use as whispering-gallery-mode optical resonators in diverse actual and potential applications, including wavelength filtering
Magazine Article
Dual-Beam Atom Laser Driven by Spinor DynamicsTBMG-1159504/01/2007
An atom laser now undergoing development simultaneously generates two pulsed beams of correlated 87Rb atoms. (An atom laser is a source of atoms in beams characterized by coherent matter waves, analogous to a conventional laser, which is a source of coherent light waves.) The pumping mechanism of this atom laser is based on spinor dynamics in a Bose-Einstein beam running-wave dipole trap that has been formed by focusing of a CO2-laser beam. By a technique that is established in the art, the trap is loaded from an ultra-high-vacuum magneto-optical trap that is, itself, loaded via a cold atomic beam from an upstream two-dimensional magneto-optical trap that resides in a rubidium-vapor cell that is differentially pumped condensate. By virtue of the angular-momentum conserving collisions that generate the two beams, the number of atoms in one beam is correlated with the number of atoms in the other beam. Such correlations are intimately linked to entanglement and squeezing in atomic
Magazine Article
Dual-Beam Atom Laser Driven by Spinor DynamicsTBMG-192404/01/2007
An atom laser now undergoing development simultaneously generates two pulsed beams of correlated 87Rb atoms. (An atom laser is a source of atoms in beams characterized by coherent matter waves, analogous to a conventional laser, which is a source of coherent light waves.) The pumping mechanism of this atom laser is based on spinor dynamics in a Bose-Einstein condensate. By virtue of the angular- momentum conserving collisions that generate the two beams, the number of atoms in one beam is correlated with the number of atoms in the other beam. Such correlations are intimately linked to entanglement and squeezing in atomic ensembles, and atom lasers like this one could be used in exploring related aspects of Bose-Einstein condensates, and as components of future sensors relying on atom interferometry.
Magazine Article
Piezoelectric Tool Actuator for Precision Turning of Turbine Shafts on Conventional CNC Lathes2002-01-257106/03/2002
A piezoelectric tool actuator system is presented for precision turning of turbine shafts on conventional CNC turning centers. The actuator system provides precise motion in the radial direction to accurately set the depth of cut in finish turning. The actuator allows for exchangeable turning tools and features a compact and self-contained design which can interface to standard turrets. Motion from the high voltage piezoelectric actuator is transmitted to the tool free of friction and backlash through the use of solid flexures. The overall stroke of the actuator is 36 μm, with a stiffness of 370 N/μm, and a natural frequency of 3200 Hz in the radial direction. A sliding mode control design provides positioning resolution of +/- 10 nm. The system was evaluated for turbine shaft machining. Tolerances on diameter of 1 μm were achieved, with an average surface roughness of 0.4 μm in machining AISI 4340 shafts (35-40 HRC). Overall the actuator demonstrated increased positioning accuracy
Woronko, Andrew, Engin, Serafettin, McIntosh, Donald G., Altintas, Yusuf
Technical Paper
Improving Thin Foil X-Ray MirrorsTBMG-745810/01/2001
A proposal has been made to develop improved thin foil, replicated conical mirrors for use in x-ray astrophysics. In the NASA astrophysical programs in which such mirrors are used, they are required to be lightweight, and to offer moderate angular resolution and high throughput to afford required sensitivity in the photon-energy band from 0.1 to 20 keV. In the proposed improvement program, emphasis would be placed on increasing resolution and diameter:
Magazine Article
SINGLE POINT BORING OF CYLINDERS AND DIAMOND TURNING OF PISTONS35002301/01/1935
Wise, W. F.
Technical Paper
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