Showing papers on "Surface finishing published in 1980"

Surface texturing of fluoropolymers

Abstract: This invention is concerned with providing improved surface texturing for adhesive bonding, metal bonding, substrate plating, decal substrate preparation, and biomedical implant applications. The invention is particularly concerned with epoxy bonding to polymers that typically exhibit low adhesion and bonding metals to a desired thickness to a polymer substrate. The surface 12 to be bonded is first dusted in a controlled fashion to produce a disbursed layer of fine mesh particles 14 which serve as masks. The surface texture is produced by impinging gas ions on the masked surface. The textured surface takes the form of pillars or cones. The bonding material, such as a liquid epoxy, flows between the pillars which results in a bond having increased strength. For bonding metals a thin film of metal is vapor or sputter deposited onto the textured surface. Electroplating or electroless plating is then used to increase the metal thickness to the desired amount.

Effects of surface finishing on stress corrosion cracking of austenitic stainless steels in high temperature water

Abstract: The intergranular stress corrosion cracking (IGSCC) susceptibility of surface finished type 304 and 304L stainless steels has been studied using a constant load tensile specimen in 288 °C water containing 26 ppm dissolved oxygen. The study was to define conditions to prevent IGSCC in piping used in a boiling water reactor (BWR). The results are as follows:

Effect of mechanical surface and heat treatments on erosion resistance

Abstract: The effects of mechanical surface treatments as well as heat treatments on the erosion resistance of 6061 aluminum alloy and 1045 steel were studied. Mechanical surface treatments were found to have little or no effect on the erosion resistance. This is due to the formation by particle impact of a work hardened surface layer regardless of the initial surface condition. The erosion resistance of Al single crystals is found to be independent of orientation. This is due to destruction of the surface microstructure and formation of a polycrystalline surface layer by the impact of erodant particles as observed by X-ray diffraction. While upon solution treatment of annealed 6061 aluminum the increase in hardness is accompanied by an increase in erosion resistance, precipitation treatment which causes a further increase in hardness results in slightly lower erosion resistance. Using two types of erodant particles, glass beads and crushed glass, the erosion rate is found to be strongly dependent on erodant particle shape, being an order of magnitude higher for erosion with crushed glass as compared to glass beads. While for erosion with glass beads heat treatment of 1045 steel had a profound effect on its erosion resistance, little or no such effect was observed for erosion with crushed glass.

Surface finishing device

Abstract: A surface finishing device operates by means of a member designed for polishing, scouring, burnishing or the like and constituted by a resilient structure allowing some distortion along its longitudinal axis. This member has an annular constriction formed from its lateral surface, being designed as bellows formed of successive frustoconical sections.

Proposed Use Of Visible Optical Techniques To Evaluate The Surface Finish Of X-Ray Optics

Abstract: Arguments leading to the tentative conclusion that production and measurement techniques developed for low scatter optical surfaces should be directly applicable to low scatter x-ray optics are briefly reviewed, and some of the more useful methods for making and testing high quality optical surfaces are discussed.

Defect-damage-resistant copper mirrors

Abstract: The calculated threshold for 10.6-μm laser-induced melting of intrinsic crystalline copper is found to be in excellent agreement with the latest experimental value when the 100-nsec pulse shape and temperature-dependent material properties are properly modeled. Melt thresholds of diamond-turned copper mirrors recently produced and tested at the Naval Weapons Center are found to be very nearly intrinsic. However, laser-induced pitting related to surface defects often causes failure at a considerably lower level. Selection of starting material and technique of surface finishing are shown to be important factors influencing laser damage related to surface defects and disorder. A well-defined inverse relationship between the thresholds for laser-induced slip and melting is demonstrated and provides a good indication of surface disorder on polished, as well as diamond-turned mirrors. Mirrors prepared by vapor deposition of copper on polished silicon carbide are found to be remarkably free of defect and visible (thermal) damage but have lower melt thresholds than good bulk copper mirrors. Thermal modeling indicates that the premature melting can be avoided by improving the thermal conductivity of the substrate.

Surface decontamination of solid waste

Abstract: This paper summarizes work in progress at Pacific Northwest Laboratory to develop vibratory finishing into a large-scale decontamination system that can minimize the volume of surface-contaminated metallic and nonmetallic waste requiring geologic disposal. Vibratory finishing is a mass finishing process used in the metal finishing industry to debur, clean and improve surface finishes. The process combines a mechanical scrubbing action of a solid medium with the cleaning action of a liquid compound. The process takes place in a vibrating tub. Tests have demonstrated the ability to rapidly reduce contamination levels of transuranic-contaminated waste to substantially less than 10 nCi/g, the current limit for transuranic waste. The process is effective on a wide range of materials including stainless steel, Plexiglas, Neoprene, and Hypalon, the principal materials in Hanford glove boxes.

Surface finishing of metallic work

Abstract: PURPOSE:To simplify the washing process and to mirror-finish the surface of metallic works by using a polishing compound solution of a moderate acidity in rough grinding and finish grinding. CONSTITUTION:In barrel-polishing the surface of metallic parts by successive rough polishing and finish polishing, a polishing compound solution of a moderate acidity between pH3.5-4 to finish the surface into mirror surface of 95+ or -5 brightness at 60 degrees incident angle so that less amount of the polishing compound remains on the surface after drying and soiling oil is hard to stick to the surface and the surface is effectively washed by ultrasonic washing using hot water instead of an alkaline solution.

Intrinsic Q of Quartz

Abstract: The proposal of Fukuyo er al. to use the -18.5" X-cut bar to estimate the intrinsic Q of quartz is examined. A description of the mount for such a bar is extracted from consideration of Ballato's motional time constant for the cut. The conclusion is that the method can probably be made to work but will be extremely difficult to implement. A benchmark against which progress can be measured is provided by the motional time constant. INTRODUCTION Fukuyo e t al. [ l ] have proposed to evaluate the intrinsic Q of quartz by measurement of the Q of a 18.5' X-cut bar. Ballato [ 21 has confirmed Warner's conjecture that the product of resonant frequency by intrinsic Q is a constant [ 31. He has developed the concept of a time constant T~ and has taught how to compute it from the viscosity matrix of Lamb and Richter [ 4 ] , [ 51. Warner's constant is just (2n71) ' . From Lamb and Richter, Ballato computes for AT-cut quartz 71 = 11.8 fs; from Warner one extracts T~ = 9.95 fs. For the purposes of this correspondence 10 fs will suffice. For the 18.5' X-cut Ballato computes Fl = 15.0 fs. These values apply to the most perfect quartz studied. Less perfect quartz will display lesser Q and greater T ~ . Some implications of Fukuyo's proposal follow [ 61 . GENERAL CONSIDERATIONS The frequency range reasonably covered by 1 8 S 0 X-cut resonators can extend from 15 kHz (170 mm long) t o 300 kHz (8.5 mm long). If the time constants are the consequences of an appropriate mechanism so that their ratio remains constant across a range of intrinsic quality, the range of Q t o be observed in a measurement can be forecast. In particular, where a 5-MHz Q of 1 X I O 6 is practically observed in a sample of quartz in a Warner resonator a 300-kHz Q of 2.2 x lo' o r a 15-kHz Q of 4.4 X I O 8 will be anticipated in the Fukuyo resonator. Since such values are not observed in extensional resonators of common experience and are not yet achieved by Fukuyo it is obvious that considerable development is necessary. Fukuyo's consideration of the various loss mechanisms identified seven. He eliminated losses in coupled modes by the proportions of the narrow 18.5' X-cut resonator. Loss due to electrodes was eliminated by using an air gap holder. Loss due to contamination was minimized by great care t o preserve cleanliness. This left the surface finish, the ambient pressure and the mounting as generators of loss mechanisms t o be investigated experimentally in order t o isolate and expose the viscous loss in the quartz. Parameter variation in investigation of each mechanism demonstrated an asymptotic Manuscript received December 19, 1978. The author is with the Mobile Radio Department, General Electric Company, Lynchburg, VA 24502. approach to a maximum of Q , but with a variety of values of the asymptote. The 18.5' X-cut resonator has absolute nodal planes perpendicular to the edges and length axis of the bar. This property allows nodal mounting of substantial area, resting the bar on a pedestal or knife edge the full width of the bar. The time constant of Ballato can assist in the understanding of the design of this kind of mount. The remainder of this correspondence is devoted to the analysis of the knife edge or pedestal mount. ANALYSIS When a number of loss mechanism can be identified, a constituent equivalent Qk can be identified with each, such that the energy loss per cycle due to each mechanism is u / Q k . When this is carried out, Q-' = X k Q i ' . If a constituent may degrade the total Q by 10 percent it must itself display a Q that is 10 times inherent and if only by l-percent its Q must be 100 times. The ratio of the mounting constituent Q, t o the intrinsic Qi can be treated as a parameter R . Consider a 1 8 . S 0 X-cut plate of length L mounted across its full width on a knife edge extending along the bar length 1. At resonance the amplitude of the fundamental standing wave with the node as origin is given by