Showing papers on "Surface finishing published in 1995"

Progress in ion figuring large optics

Abstract: Ion figuring is an optical fabrication method that provides deterministic surface figure error correction of previously polished surfaces by using a directed, inert, and neutralized ion beam to physically sputter material from the optic surface. Considerable process development has been completed and numerous large optical elements have been successfully final-figured using this process. The process has been demonstrated to be highly deterministic, capable of completing complex-shaped optical element configurations in only a few process iterations, and capable of achieving high- quality surface figure accuracies. A review of the neutral ion beam figuring process will be provided, along with discussion of processing results for several large optics. Most notably, processing of Keck 10 meter telescope primary mirror segments and correction of one other large optic where a convergence ratio greater than 50 was demostrated during the past year will be discussed. Also, the process has been demonstrated on various optical materials, including fused silica, ULE, zerodur, silicon, and chemically vapor deposited (CVD) silicon carbide. Where available, results of surface finish changes caused by the ion bombardment process will be discussed. Most data have shown only limited degradation of the optic surface finish, and that it is generally a function of the quality of mechanical polishing prior to ion figuring. Removals of from 5 to 10 micrometers on some materials are acceptable without adversely altering the surface finish specularity.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Polishing process for concave lightweight silicon-coated silicon carbide optics

Abstract: Advanced optical systems, currently under consideration, propose the use of lightweight, segmented, long radii elements. Reaction-bonded silicon carbide (RB SiC) is quickly becoming a contender in the materials market for these large, lightweight mirrors due, in part, to its relatively low thermal expansion and high stiffness to weight ratio. The RB SiC manufacturing processes can be considered advanced in comparison to the polishing and finishing processes on bare RB SiC, or on clad RB SiC substrates. In an effort to improve the polishing and finishing techniques, Eastman Kodak Company has investigated a polishing process for physical vapor deposited silicon (PVD Si) coated RB SiC optics and has demonstrated this process on a lightweight, concave, PVD Si-coated RB SiC hexagonal optic. This discussion includes the modification and redesign of an existing conventional planetary table, durability test results on the PVD Si/RB SiC coating bond, process approach and results for the hexagonal demonstration piece, and the thermal stability analysis of the hexagonal mirror upon completion of polishing and ion figuring the front surface of the mirror.

Method of surface finishing of metal moldings

Abstract: A method for producing a vehicle wheel having a polished design surface coated with a transparent coating, comprising the following steps of: producing a vehicle wheel having a design surface thereon; and coating said design surface with transparent composite material which is mainly composed of inorganic material.

Method for forming a roller compacted concrete industrial floor slab

Abstract: A roller compacted concrete industrial floor slab is formed by surface finishing the slab by using a separate thin topping bonded to a roughened surface of the RCC, or by manipulating the RCC surface itself by working into its surface a finish mixture of cement-coated, rice-sized grit in a moisture saturated condition to fill any voids in the surface.

Effects of surface chromium depletion on localized corrosion of alloy 825 as a high-level nuclear waste container material

Abstract: Effects of the chromium-depleted, mill-finished surface on the localized corrosion resistance of alloy 825 (UNS N08825) were investigated. Tests were conducted in solutions based on the ground water at Yucca Mountain, Nevada, but with a higher concentration of chloride (Cl−). Results indicated that breakdown (Ep) and repassivation (Erp) potentials for mill-finished surfaces were more active than those for polished surfaces. Potentiodynamic polarization tests indicated pits could be initiated on the chromium-depleted surface at potentials of 220 mVSCE in a solution containing 1,000 ppm Cl− at 95°C. Potentiostatic tests identified a similar pit initiation potential for the mill-finished surface. However, under long-term potentiostatic tests, a higher potential of 300 mVSCE was needed to sustain stable pit growth beyond the chromium-depleted layer. An increase in surface roughness also was observed to decrease localized corrosion resistance of the material.

Ion beam surface treatment: a new technique for thermally modifying surfaces using intense, pulsed ion beams

Abstract: The emerging capability to produce high average power (10-300 kW) pulsed ion beams at 0.2-2 MeV energies is enabling us to develop a new, commercial-scale thermal surface treatment technology called Ion Beam Surface Treatment (IBEST). This new technique uses high energy, pulsed (/spl les/500 ns) ion beams to directly deposit energy in the top 1-20 micrometers of the surface of any material. The depth of treatment is controllable by varying the ion energy and species. Deposition of the energy in a thin surface layer allows melting of the layer with relatively small energies (1-10 J/cm/sup 2/) and allows rapid cooling of the melted layer by thermal conduction into the underlying substrate. Typical cooling rates of this process (109 K/sec) are sufficient to cause amorphous layer formation and the production of non-equilibrium microstructures (nanocrystalline and metastable phases). Results from initial experiments confirm surface hardening, amorphous layer and nanocrystalline grain size formation, corrosion resistance in stainless steel and aluminum, metal surface polishing, controlled melt of ceramic surfaces, and surface cleaning and oxide layer removal as well as surface ablation and redeposition. These results follow other encouraging results obtained previously in Russia using single pulse ion beam systems. Potential commercialization of this surface treatment capability is made possible by the combination of two new technologies, a new repetitive high energy pulsed power capability (0.22 MV, 25-50 kA, 60 ns, 120 Hz) developed at SNL, and a new repetitive ion beam system developed at Cornell University.

Both surface polishing machine with surface finishing device

Abstract: PURPOSE:To rapidly conduct surface finishing of a surface plate with little wear of the surface plate to stabilize surface plate surface accuracy by arranging a base table on a bar frame via an inclination angle adjusting device, and also providing a displacement sensor on a moving body. CONSTITUTION:After lathe turning, a flatness shape of a lower surface plate 12 is first measured, based on the result thereof a bolt 62 is advanced/retracted vertically by screw-engagement operation to swing a base table 41 up and down with a pair of ball support tools 61 as fulcrums so as to integrally incline a moving body 44 and the like, and inclination of a surface finishing device 40 is thereby finely adjusted. A displacement sensor 65 is fitted to a tip holding tool 45, and while a measuring element thereof is in contact with an upper surface of the lower surface plate 12, the moving body 44 is moved in the radial direction so as to measure inclination of the surface finishing device 40 with respect to the flatness shape of a surface of the lower surface plate 12. In the case where this measured value is not a specified inclination value, an inclination angle adjusting device 60 is again operated to finely adjust the inclination of the surface finishing device 40, and the inclination of the device 40 is measured by means of the displacement sensor 65.

Car body alloys and methods of corrosion protection: Aluminium Sheet

Abstract: The aluminium industry supplies various car body sheet qualities tailor-made to meet the requirements of the car producers. The most important alloy types are AlMgSi (free from stretcher-strain markings after forming and hence suited for outer skin) and AlMg (for interior use). In addition to the significant weight savings it is its long service life which makes aluminium an attractive alternative to steel sheets. A prerequisite for good corrosion resistance is a surface treatment optimised for aluminium. This includes the creation of a phosphate surface layer to allow lacquer coating together with steel and galvanized steel on existing lines. The Accelerated Outdoor Exposure Test (VDA 621–414) proved to be the only static corrosion test method suitable for assessing the resistance level of the final lacquered car body. In addition to the proper selection of alloy and surface finishing technique it is important that some aluminium-specific precautions are taken during manufacture if the full long service potential of the material is to be realized.

Mechanical reliability of 8-m class ULE glass telescope blanks during manufacturing

Abstract: The manufacture of 8m class ULETM glass telescope mirror blanks involves multiple steps each of which can induce both stresses and flaws. To ensure the mechanical reliability of such large mirror blanks, both during and post-manufacturing, extreme care is required in the various process steps (including handling, grinding, finishing, and transportation) so as to limit the stress and flaw severity to below the threshold level for the specific surface finish. This paper examines the critical stress/time histories the blanks experience during manufacturing and their ability to initiate slow crack growth from grinding flaws. Two different surface finishes, namely 120 grit and 270/325 grit, with and without acid etching are characterized with respect to strength, flaw, and fatigue behavior. These data show that the 270/325 grit finish with acid etching is appropriate for the sagging step which imposes a static stress of 650 psi in the center region of the mirror blank over a two-week sag period. Similarly, the 120 grit surface finish is adequate for grinding, packaging, and transporting steps which impose a static stress of 435 psi in the support pad region for a three month period. These predictions, based on power law fatigue model, were verified by conducting static fatigue tests (at appropriate stress levels) on a large sample of 6 inch diameter ULETM discs (with appropriate surface finish) at 25 degrees C and 100% RH. A comparison of strength distribution of the discs, before versus after static fatigue tests, showed no changes in strength indicating absence of slow crack growth at stresses and environment representative of manufacturing process. Such a verification is imperative for selecting appropriate surface finishes for the mirror blanks to ensure their mechanical reliability during manufacturing.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Surface finishing treatment

Abstract: PURPOSE:To facilitate handling of a large number of small treated articles and prevent marring of large treated articles due to reciprocal contact CONSTITUTION:By storing a treatment liquid 41 and granular bodies 42 in an oscillating tank 1 supported free to oscillate, storing treated articles 43 in wire bodies 44 or a cage body constituted of wire rods 45 the outer surface of which is covered with an elastic body and with mesh size for the granular bodies 42 free to pass through, storing it in the oscillating tank 1 and reciprocally oscillating the oscillating tank 1 in that state, surface finishing treatment is carried out

Surface finishing method

Abstract: PURPOSE:To allow a wall, a floor, and the like to be finished in the form of using natural stones and artificial stones CONSTITUTION:A mortar layer 2 is provided on backing material 1, and the surface of the mortar layer 2 is scraped off to form stone material parts 3 and a joint part 4 Primer 5 is then applied to the stone material parts 3, and a surface finishing agent 6 is further applied thereto The surface finishing agent 6 is prepared by mixing rock paint, white cement and a solvent A color tone adjusting agent 7 prepared by diluting picture painting oil is then applied thereto Joint material 8 is fitted, and lastly a protective shield 9 is applied thereto

Multi-layered structural body and manufacture thereof

Abstract: PURPOSE:To obtain a multi-layered structural body, useful for the replaced material of wood, by a method wherein at least one surface of the outermost layers of an integrated body, having an integral structure made by combining a cured layer, constituted by curing a mixture containing crushed or split used paper and thermosetting resin, with the surface material layer arbitrarily, is made by the surface material layer. CONSTITUTION:A surface material is arranged under a condition that the same is contacted with both surfaces or one surface of a precursor, formed of a mixture containing at least used paper, fibrous substance, added if necessary, and a thermosetting resin, the laminated body of the precursor or a multi-layered precursor, in which the surface material is arranged between a plurality of precursors. The structural body is heated by ventilating heating, oven heating or the like or the precursor is cured by heating and pressurizing through a press machine, a draw-forming machine, an extruder or the like, then, the precursor is integrated with the surface material. According to this method, not only a plate, having a multi-layered structure consisting of the surface material and cured body, but also a continuous plate having a curved surface, can be formed and, further, the surface material can be manufactured by bonding a soft surface finishing material through an adhesive agent, if necessary.

Polishing material for soft member

Abstract: PURPOSE:To carry out the speedy mirror surface finishing having the excellent surface smoothness, exceedingly suppressing the generation of scratch, etc., in the polishing finishing by forming a soft material for a soft member from the alpha-alumina particle having a relative polishing speed for the ferrite single crystal of a prescribed value or more. CONSTITUTION:A polishing material for a soft member consists of alpha-alumina particles having a relative polishing speed for the ferrite single crystal of 300% or less and an average primary particle diameter of 0.1-1.0mum. Accordingly, in comparison with the case where the polishing time of 90min. is necessary with a solid portion concentration of 6wt.% in use of magnesia, the solid portion concentration can be reduced to about 2wt.%, and also the polishing time can be reduced to about 20min. by using alpha-alumina. Further, the fine polishing work for the soft member can be carried out with the excellent surface smoothness in an aqueous solution.

Inner cylinder internal surface finishing method for workpiece and honing head structure using this method

Abstract: PURPOSE:To provide an inner cylinder internal surface finishing method for a workpiece and a honing head structure using this method wherein reducing a process is attained so as to obtain a plateau surface by a single process without adding an exclusive use process. CONSTITUTION:In the case of finish working an internal surface of an inner cylinder B of a workpiece CB by a grinding wheel 5 provided in the point end peripheral part of a rotatable and reciprocation-movable honing head 1, after finish working with finishing rough abrasive grains 5A provided mixing in the grinding wheel 5, plateau working is performed with plateau use fine abrasive grains 5B provided mixing in the same grinding wheel 5. Further, the grinding wheel 5, provided in the point end peripheral part of the honing head 1, is constituted in a condition that the rough abrasive grains 5A secured by a soft binder J is provided to mix in the fine abrasive grains 5B.

Surface finishing method for magnetic disk substrate and its device

Abstract: PURPOSE:To obviate the degradation in smoothing effect, to enable long-term grinding and to improve productivity by rapidly and repetitively executing supply and discharge of an abrasive liquid intruding between the recesses of a grinding tool and a magnetic disk substrate to a grinding surface. CONSTITUTION:The magnetic disk substrate 11 having microprojections 15 is subjected to surface grinding, by which these microprojections 15 are removed and the smooth surface is obtd. This surface finishing device is provided with a grinding tool 13 which forms an outside shape having plural pieces of ruggedness by connecting plural spherical members 13a to a rosary shape and has the length approximately equal to the length extending to the grinding region in the radial direction of the magnetic disk substrate 11. The projecting parts of this ground tool 13 are pressed to the rotating magnetic disk substrate 11 and is moved back and forth at about one pitch of the ruggedness described above in a radial direction and the substrate is ground while the abrasive liquid is supplied thereto.

Method for quality-controlled refining of a surface with radiation-cured surface refining

Abstract: A process for the quality-controlled finishing of a surface with a radiation-cured surface coating (I) comprises coating with a finishing formulation (II) contg. an indicator with proton-affinity (III), crosslinking (II) by irradiation and using ion mobility spectrometry (IMS) to detect any (III) escaping from the printed surface after curing. Also claimed is formulation (II) contg. indicator (III) which can be detected by IMS. Also claimed is a quality control appts. for surface finishing, with an IMS spectrometer (1) fitted with a gas inlet (11) connected to a suction head (6), the edge of which can be positioned at a min. distance from the surface of the printed prod. (2) (see Fig.1).

Outside angle processing method

Abstract: PURPOSE:To set an outside angle part favorably, finish it to have excellent appearance, and improve durability in finishing it using a dry surface finishing material in construction finishing CONSTITUTION:A surface finishing material 1 comprises a rectangular decorative material part 1a comprising a molded matter and a painted film, and a base material part 1b comprising nonwoven fabric, glass cloth, synthetic paper, etc, as main constituents In the meanwhile, end parts of two surface finishing materials to be applied on an outside angle line on the body side are cut or planed, an angle member to be applied on an outside angle like a belt is two- folded, and the surface finishing material 1 of which end parts are worked is applied from an end of a fold line to form an outside angle accessory An adhesive is applied on an end part of the outside angle accessory, and on backing of a wall surface or the like at a corresponding part to a width of the outside angle accessory The adhesive leaking from an outside angle line part of the outside angle accessory is cut or planed to process the outside angle

Development of an automatic surface finishing system (ASFS) based on closed-loop surface topography control

Abstract: Surface finishing accounts for up to 50% of the total time required to produce a mold or die, and most finishing operations are still performed manually. The objective of this paper is to develop an automatic surface finishing system (ASFS) based on closed-loop surface topography control. A process planner module has been used in the developed ASFS to select different finishing levels and finishing strategies based on the design specifications in CAD design databases and surface topography analysis. A prototype ASFS has been constructed to serve as a platform to perform experiments to verify the approach. Experimental results have proven the feasibility of the concept.

Application of optical scattering in multichip module processing

Abstract: The impact of surface characterization on various aspects of microelectronic device performance and manufacture is briefly reviewed. Optical scattering measurements have been carried out for the surface characterization of AlN, MgO, Al2O3 substrates, single crystal silicon wafers and physcial vapor deposited films. Scattering light was recorded up to 80 degree from the specular direction. The angle-resolved scattered light sensitively reveals the characteristics of surface in the spatial frequency domain. Quantitative parameters of surface roughness have been derived from power spectral density distributions and diffraction theory for highly polished smooth surfaces. Instrumentation for full surface characterization has been coupled with computer operation. It has the features of high-speed and noncontact and is inherently area averaging. It lends itself particularly well to online product of high- speed and inprocess monitoring of a manufacturing process. Delicate surfaces can be rapidly 'finger printed'.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Effect of processing parameters on surface finish for fused deposition machinable wax patterns

Abstract: This report presents a study on the effect of material processing parameters used in layer-by-layer material construction on the surface finish of a model to be used as an investment casting pattern. The data presented relate specifically to fused deposition modeling using a machinable wax.