Showing papers on "Surface finishing published in 2003"

Surface roughness of composite resins after finishing and polishing

Abstract: This study evaluated the effect of surface finishing methods on the average surface roughness of resin composites. Seven composites and two polishing systems were used. One hundred and twenty-six conical specimens of each material were prepared in stainless steel molds against a polyester strip. Forty-two of them remained intact and were used as controls. Each half of the remaining samples was polished with either diamond burs or diamond burs + aluminum oxide discs. The results showed no statistical difference in average surface roughness (Ra, µm) between the polyester strip and aluminum oxide discs (p>0.05). However, finishing with diamond burs showed a statistically higher average roughness for all composites (p<0.05). Statistical differences were detected among materials (p<0.05) in the use of diamond burs.

Breakdown voltage of electrode arrangements in vacuum circuit breakers

Abstract: The prediction of HV strength of electrode arrangements in vacuum is complex. A comparison of experimental results from different labs is quite difficult, because they are influenced by a wide range of parameters like electrode material, surface finish, surface area, conditioning state of the surface and the geometry of the electrode arrangement. The aim of this work is to find an empirical relation between the breakdown voltage and different electrodes parameters. Shielding arrangements and main contacts of vacuum tubes are of particular interest. For this purpose, models of contacts and shield electrodes made of stainless steel are stressed with lightning impulse voltage. Several methods of surface finishing are applied to obtain reproducible conditions. The experimental results and deliberations for an empirical approach are presented. In addition the results are related to numerical field calculations.

Morphology of metal surface generated by nylon/abrasive filament brush

Abstract: Nylon/abrasive brushing tools are used in surface finishing processes for a wide range of applications, including blending, polishing and edge-radiusing of both ductile and brittle materials In this paper, the surface topography and machined materials that are generated during orthogonal brushing of a flat 6061-T6 workpiece are examined using scanning electron microscopy Also, the microscopic morphology of nylon/SiC filaments is examined in as-received and steady-state configurations This information is used to postulate a qualitative model for material removal mechanisms and the wear/attrition characteristics of the filament material system

Zirconium-phosphate films self-assembled on aluminum substrate toward corrosion protection

Abstract: Zirconium-phosphate self-assembled films and their derivatives have been developed on aluminum alloy, AL1100. The characterizations of the self-assembled zirconium phosphate layers were executed by X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and atomic force microscopy. To examine the resistance of the films against corrosion, a salt-spray test has been executed. The test results have indicated that self-assembled zirconium-phosphate derivative films effectively protected aluminum substrates. In particular, the multi-layered zirconium-phosphate film fabricated by adsorbing 1,12-dodecyldiphosphonic acid has shown superior anti-corrosion properties to AL1100. The zirconium-phosphate self-assembled monolayers would be promising for surface finishing.

The effect of modifications to the nickel/gold surface finish on assembly quality and attachment reliability of a plastic ball grid array (peer review version)

Abstract: Electrolytic and electroless Ni/Au are common pad surface finishes on area array (BGA or CSP) packages and printed wiring boards (PWB). The electroless nickel/immersion gold (ENIG) process often is implemented when there is insufficient space to allow bussing for the more common electrolytic Ni/Au plating. The ENIG process continues to be used despite evidence that it may cause catastrophic, brittle, interfacial solder joint fractures. In this investigation a plastic ball grid array (PBGA) test vehicle is used to compare quality and reliability of standard and experimentally modified ENIG surface finishes. The standard electrolytic Ni/Au surface finish is used as the control cell for the experiment. Ball shear tests and optical and scanning electron microscopy are performed on as-received and thermally preconditioned packages to evaluate package quality prior to assembly. Accelerated temperature cycling (0/+100/spl deg/C and -40/+125/spl deg/C) is used to evaluate solder joint attachment reliability. Detailed failure mode analysis is used to compare the fracture modes in the ball shear and thermal cycled samples in the electroless and electrolytic packages. The results are discussed in terms of the failure modes and the characteristics of the different Ni/Au surface finishes.

Influence of the mechanical and metallurgical state of an Al-Mg alloy on the surface integrity in ultraprecision machining

Abstract: This work presents the experimental results of the facing turning of an Al-Mg alloy. This aluminium alloy was mechanically and metallurgically modified, by means of cold rolling reduction and refining grain size previous to machining. The samples were cut and compared with samples in the as-received form, machined under the same cutting conditions. Surface finishing and work hardening were measured. Results show that theoretical surface roughness values are always smaller than the measured ones for all samples. Also, the surface roughness of the as-received samples is larger than that of mechanically modified samples. This difference of surface roughness was attributed to the swelling effect of the material. Microhardness values of the machined samples showed a decreasing trend with increasing loads. The surface of the cold rolled sample did not present a detectable microhardness alteration. Optical microscopy was used to observe qualitative aspects of the machined surface.

Laser polishing of silica slotted rods

Abstract: Lasers have been widely used in surface modification. In the present research, a CO2 continuous wave laser has been used to polish slot surfaces of silica rods. Strong absorption of 10.6 μm CO2 radiation by the silica surface promotes softening of a very thin layer of material that flows under the action of surface tension forces. A smooth surface forms, which decreases the surface roughness without substantial change in surface geometry. The effect of laser-surface inclination angle on the requisite power requirement has been assessed experimentally and theoretically. Using a computer controlled laser beam scanning system, reliability and reproducibility have been greatly improved compared with an alternative surface finishing method, manual fire polishing.

AFM in surface finishing. Part II. Surface roughness

Abstract: This practical topics paper, the second in a short series concerning the use of atomic force microscopy (AFM) in surface finishing, focuses on various types of surface roughness measurement that can be obtained from AFM data. Surface roughness can greatly affect optical, tribological and catalytic properties of surfaces. Roughened surfaces also have implications in biofouling due to the increased number of contact points for bacterial attachment as well as protection of these cells from shear forces.

Improving the performance of aerospace alloys

Abstract: This paper reviews the role of alloying elements in aluminium and alloy fabrication on performance during surface treatment and surface finishing. Such elements may be present in solid solution as fine segregates, strengthening phase and equilibrium phases. For surface treatment and finishes, which generally proceed in the presence of alumina film, knowledge of the processes proceeding at the alloy/film and film/electrolyte interfaces, and those within anodic alumina films, gives rise to the possibility of controlling features of nanoscale dimensions, for improved performance, arises. Its influence on nanotextures at treated surfaces and compositionally and morphologically modified films is explained briefly.

Effect of rough surfaces on rolling contact fatigue theoretical and experimental analysis

Abstract: Today, Rolling Contact Fatigue (RCF) is essentially caused by surface originated failures. This failure mode is often linked to surface defects like dents due to oil contamination [1, 2, 3] or surface finishing [4]. For example, the surface roughness has an influence on both the risk of EHL film collapse and the stress level in the contacting bodies. Consequently, the induced damage could either be scuffing or micro and macro spalling. In this paper, the authors have developed an analytical model using Fast Fourier Transforms (FFT) in order to evaluate the pressure increase due to the roughness profile under elastic dry contact assumptions. Using this method it is possible to determine the pressure field and the induced stress distribution for real surfaces. Moreover, the more dangerous wavelengths and/or amplitudes of the roughness can be identified. Ball bearings with two different surface finishes were produced. Roughness profiles were measured before and after the running in process and used in the model in order to evaluate the maximum shear stress level encountered in the elastic bodies. These ball bearings were then fatigue tested until failure. The operating conditions are representative of automotive applications. The encountered damage is clearly initiated at the surface. An analysis of the surface roughness influence on the damage encountered in rolling element bearings is proposed. The experimental fatigue life reduction is linked to the numerical results.

Apparatus and procedure for surface finishing of pipes by means of lamellar wheels

Abstract: For satin finishing or polishing of its outer surface, a pipe (T1, T2) is fed in a direction defined by its axis and turns around its own axis as it advances. The finishing is performed by means of a pack of lamellar wheels (S) which rotates around an axis ( a 30) parallel to the axis of the pipe and is carried by a sleeve supported on a rocker arm, so that it is possible to adjust the position thereof with respect to the pipe.

Surface finishing layer capable of attaching to metal and nonmetal and preparing process thereof

Abstract: A process for attaching a decorative layer to the surface of metal or non-metal workpiece includes spraying the artistic glass paint on the surface of workpiece, fixating the pattern at temp which is10-15 deg.C lower than ordinary temp, drying, spraying water polyurethane paint and then oily enamel paint, and baking at 80-100 deg.C for 2-8 hr.

Film surface finishing system

Abstract: This invention provides a flexible film for providing a protective finish on a surface. The film may optionally include a bonding coat for attaching the film to the surface, at lest one removable protective layer, and a release coating for facilitating the transfer of the film to the surface. Cured and crosslinked top coats maybe applied over the films to enhance the durability of the underlying surface, These top coats may then be easily removed by peeling the underlying flan away from the surface.

Surface Finishing for Biomaterials: Application of the Elid Grinding Method

Abstract: Conventional biomaterials, such as titanium alloys, require enhanced chemical stability and wear resistance, which are dependent on the quality of the surficial oxide layer. However, it is very difficult to produce a sufficiently homogenous oxide layer by polishing using isolation abrasive alone. In our previous study, we proposed a new electrical grinding method (ELID grinding). The process improves oxide formation on the finished surface, resulting in finished surfaces with very thick and potentially stable oxide layers. In this study, to ensure the fabrication of surface with desirable characteristics for biomaterials, three types of specimens, which were processed with different surface finishing methods were prepared. Processed surfaces were analyzed by using an Energy Dispersive X-ray analyzer (EDX). To measure the thickness of surface oxide layers, detailed observation were performed by using a Transmission Electron Microscope (TEM). Although the ELID ground surface shows a higher value of surface ...

Liquid carbon surface during explosive emission

Abstract: It has been established that the surface layer of carbon emitter is getting liquefied during an explosive electron emission (EEE) pulse to form very fine (on the scale of nanometers) tips with top curvature radii r<10 nm. Such tips are evenly distributed over the carbon emitter surface with a density on the order of 108 cm−2. One can surmise that it is these tips that secure a high stability and reproducibility of EEE from carbon emitter surfaces. A phenomenon of “electropolishing” of the carbon surface has been discovered which occurs when ions are extracted from the explosive emission plasma. It is experimentally demonstrated that taking off of the ion current gives rise to conditions ultimately resulting in a discontinuation of the formation of microprojections at the emitter surface, with the carbon emitter surface becoming more smooth (“polished”), and with the emergence of a new EEE cycle hampered.

AFM in Surface Finishing: Part III - Lateral force microscopy and friction measurements

Abstract: This paper is the third in a series of practical topics on the use of atomic force microscopy (AFM) in surface finishing and focuses on lateral force microscopy (LFM) as a method for obtaining frictional, or tribological, data. This AFM technique monitors the lateral twisting of the cantilever as it is rastered over the sample's surface. The resulting image, which can be obtained simultaneously with the topography (height) image, shows contrast between areas with differing frictional properties. LFM has been applied to the study of a wide range of systems, including: single crystals, alkanethiols on golds, silanes on glass, conducting polymers, polyurethanes and biological surfaces.

Improved materials meeting the demands for EUV substrates

Abstract: The enhanced demands for substrate materials for next-generation optics and masks have initiated detailed investigations on Zerodur as a proposed EUVL substrate material with focus on thermal expansion behavior and surface roughness. As a result of specifically adjusted process parameters, the coefficient of thermal expansion (CTE) was tailored to be a minimum at 22.5°C. Laboratory samples of Zerodur exhibit a CTE < 5 ppb/K corresponding to the lowest expasnion class of the SEMI standard P37 (19 to 25°C) for EUV mask blanks. By further variation of process parameters, the position of zero crossing, e.g. at 30°C, can be varied, revealing an attractive attribute feature of Zerodur. A new dilatometer type was mounted in 2002 with first operatinoal results revealing an improved reproducibility of ~1ppb/K in the temperature range of 0 to 50°C. A series of CTE measurements with a small block of Zerodur provides information on CTE homogeneity on a cm-scale: No CTE variation was observed within the error of measurements for a block exhibiting ± 3.5*10-6 vairtion in refractinve index. CTE variation can cause surface deformations during changing temperature conditions. A first setup of Fizeau-Interferometer with a current resolution of 0.3 nm rms was used to record surface deformation of Zerodur due to elevated temperature was determined to be lower than the current resolution. Both methods to analyze the CTE homogeneity of Zerodur lead to the result of CTE variation below 1 ppb/K, still identifying today's need to improve metrology further. Final finishing of EUV substrates may increase roughness of super-polished surfaces significantly. Using appropriate processes a to surface roughness < 0.25 nm rms under production conditions can be achieved after final finishing of Zerodur. As an improved Zerodur-type material, recent achievements of material development demonstrate the optimization of glass-ceramic composition to nearly meeting the specification of surface roughness after a standard finishing process. These results are regarded as a promising milestone to develop an optimized glass-ceramic material providnig adjusted thermal expansion behavior and surface processability according to the specific demands of EUV technology.

Polymer material and casting process development for reduced manufacturing cost of spaceborne optics

Abstract: There is a significant amount of research devoted to developing materials and processes for spaceborne mirrors. Carbon fiber mirrors and advanced ceramic mirrors such as SiC are being developed. These materials provide excellent stiffness to weight ratios and thermal stability. The principal problem with using these lightweight materials for mirrors is the difficulty of polishing the surface to achieve the required optical quality finish. Carbon fiber mirrors also suffer from fiber print through and ceramic mirrors are difficult and costly to polish due to the material hardness and porosity. SRS has been developing processes for depositing a very thin, optical-quality membrane layer of space-qualified polymer onto the surface of a mirror still in a rough-polished state to eliminate the need for expensive and time consuming final surface finishing of lightweight mirrors. By flow casting a polymer onto the surface, remaining peaks and valleys are filled in resulting in an extremely smooth surface. Initial research has shown that the membrane mirror surface can have a significantly better surface finish than the casting substrate, thus eliminating the need for costly final polishing.

Surface finishing of resin-modified glass ionomer.

Abstract: This study utilized spectrophotometry to evaluate in vitro superficial dye deposition on resin-modified glass ionomer, following different surface finishing and polishing treatments. Materials that were photocured adjacent to the mylar strip produced the surfaces with the lowest mean after superficial staining. A restorative technique without excesses resulted in a smoother surface and prolonged the life of the restoration. The resin-modified glass ionomers tested offer adequate clinical performance.

Powder driven surface finishing apparatus

Abstract: A surface finishing device includes a surface finishing drum having opposing ends and a chamber therebetween, an elongate fixture having a handled proximal extremity and an opposing distal extremity, and a support element, which is carried by the distal extremity and extends through one of the ends of the surface finishing drum into the chamber. An electric motor is disposed in the chamber and is carried by the support element. A drive shaft is also disposed in the chamber and couples the motor to the other of the ends of the surface finishing drum.

Surface finishing method for aluminum or aluminum alloy material

Abstract: PROBLEM TO BE SOLVED: To provide a surface finishing method whereby the surface of an aluminum alloy material can be finished by electrolytic polishing while preventing whitening without fail SOLUTION: The aluminum alloy material and a platinum electrode are immersed in an aqueous sodium nitrate solution with a 20 mass% concentration This aqueous sodium nitrate solution is made neutral and does not contain chlorine ions The aluminum alloy material is used as an anode; and the platinum electrode, as a cathode Direct current with a current density of 1 Acm -2 or higher is caused to flow in the aqueous sodium nitrate solution to electrolytically polish the surface of the aluminum alloy material COPYRIGHT: (C)2003,JPO

Surface treating method and ornamental article

Abstract: PROBLEM TO BE SOLVED: To provide an ornamental article having excellent durability and excellent aesthetic appearance and to provide a surface treating method which makes it possible to obtain the above ornamental article. SOLUTION: This surface treating method comprises irradiating at least a portion of the surface of a base material 2 composed mainly of a metallic material with a YVO4 laser, thereby forming color change sections 21 of blue, purple, yellow or white. The base material 2 is preferably at least partly formed of Ti or stainless steel. The spot diameter of the YVO4 laser is preferably 20 to 80 μm. The base material 2 is preferably at least partly subjected to surface processing of at least one selected from mirror surface finishing, satinizing and graining.

Surface finish material in building room and finishing method using the same

Abstract: PROBLEM TO BE SOLVED: To provide a surface finish material in building room which enhances the strength and execution property and has a function of adsorbing and decomposing domestic malodor, nicotine of tobacco, bacteria and harmful chemical substance, and to provide a surface finishing method using the same SOLUTION: This surface finish material in building room is made by using white shirasu as main raw material and blending burnt gypsum, volcanic ash and removed titanium oxide for photocatalyst Furthermore, this surface finish material in building room consists of white shirasu 45-55%, burnt gypsum 35-45%, volcanic ash 9-15%, titanium oxide for photocatalyst 05-5%, inorganic pigment 02-4%, natural hemp fiber 01-05%, curing retarder 001-02% and Metolose (registered trade mark) 01-05% or red algae 01-03% COPYRIGHT: (C)2003,JPO

Trapping of electrical charges and laser damage

Abstract: The polishing of optical components introduces defects in subsurface that can contribute to the damage initiation and the decrease of optical performance. These defects can trap electric charges or could be precursors to color center. We have proposed to study subsurface defects generated by the surface finishing by using trapping of charges and cathodoluminescence measurements. These two techniques are complementary: the cathodoluminescence gives information on defects having radiative decay and the grounded current can also be sensitive to other defects having non-radiative decay. It is shown that they are able to distinguish the surface finishing of natural silica. The defects are mainly concentrated in the first micron layer. We have also found that the repartition of defects on the surface in not homogeneous.

Indentation hardness and modulus of the surface of a large super-polished single crystal silicon sphere

Abstract: Surface properties of single crystal silicon are of great interest to many people in research and development as well as in industry, particularly the semiconductor industry. In this paper we present and discuss the results of a series of nanoindentations as they relate to the elasticity and microhardness properties on the surface of a large single crystal silicon sphere. The sphere is 94 mm, it has a total roundness error of and the directions. We show how these differences affect the overall shape of the sphere during the surface finishing process.

Polishing tool and nc grinding machine using the same

Abstract: PROBLEM TO BE SOLVED: To provide a polishing tool for enabling mirror surface finishing on a condition that a grinding wheel is a dry type and a wafer W is a wet type and reduction of environmental load by reducing amount of etching chemical liquid after grinding and reducing colloidal silica, and a NC (numerical control) grinding machine using the same. SOLUTION: This polishing tool 12 performs mirror surface finishing for surfaces of electronic parts such as a semiconductor wafer and an aluminum hard disk. In the polishing tool 12 in which soft abrasive grain having a chemical action is made as a fixed abrasive grain grinding wheel 5, a ring-shaped cover 1 is provided on an outer peripheral surface side of the polishing tool 12 and a ring-shaped cover 6 is provided on an inner peripheral surface side. COPYRIGHT: (C)2005,JPO&NCIPI

Curved surface finishing method and its device

Abstract: PROBLEM TO BE SOLVED: To machine a curved surface portion of a workpiece speedily, at low cost, and with uniform precision. SOLUTION: This device performs curved surface finishing for the curved surface WC rotating around a rotation axis WL of the workpiece W supported rotatably, comprising an air bag 3 which supports an abrasive film SP, follows the curved surface WC of the workpiece W, and can move in the direction of the rotation axis WL of the workpiece W; and an abrasive cloth and paper supply mechanism 10 for supplying the abrasive film SP continuously in the direction orthogonal to the rotation axis WL of the workpiece W and in the tangential direction of the curved surface WC. Unused portion of the abrasive film SP supplied by the abrasive cloth and paper supply mechanism 10 is pressed to the curved surface WC of the rotating workpiece W with air pressure.