preservation and cleaning of fractures for fractography

reviews various fracture preservation and cleaning techniques for fractography. these techniques apply essentially to chemical damage. the preservation techniques include storing fractures in moisture limiting containers (i.e. desiccators) and using corrosion-preventative surface coatings such as axle grease, adherent plastic coatings, an..

description of a unique machine tool permitting achievement of <15-aa rms diamond-turned surfaces

the cutting tool is programmed to move in 4-nm increments along an x axis and an omega axis. exceptionally stiff and accurate control of the tool is possible with this system. copper surfaces of revolution have been produced with a 12.3-aa rms surface finish and a contour accuracy of 75 nm. in conjunction with a thermally stabilized air b..

high strength furnace-drawn optical fibers

the tensile strength of optical fibers, drawn with a zirconia induction furnace, coated with a silicone-nylon composite, and tested using 20 meter gauge lengths is reported. by controlling the process variables, kilometer lengths of fiber with strengths greater than 4.2 gn/m/sup 2/ have been produced. the effects of preform surface treatm..

surface pre-treatment process for tantalum contacts

describes a method by which the desirable properties of sputtered ta can be combined with those of evaporated ta with minimum manufacturing tool impact. a surface pre-treatment is done with 20-50 aa of sputtered ta immediately prior to the standard evaporations. this very thin sputtered ta layer does not cause 'fences', and does not lead ..

some aspects of manufacturing techniques in instrument production

certain modern production techniques are particularly suitable for high precision fabrication of components made of a wide variety of materials, including metals, alloys, plastics, ceramics, stone and glass. the availability of these techniques has in turn influenced the development and design of new instruments. the processes discussed i..

effect of secondary coating technique of low-loss optical fibers on transmission loss

secondary coating of optical fibers has been investigated for the purpose of establishing the coating techniques which are able to preserve the excellent transmission properties of bare fibers several kinds of plastic resins as the material of secondary coating have been coated on fibers by two different draw-down ratios. it is has been d..

electron beam induced current studies of ms and mis devices on cds

schottky diodes prepared by depositing gold onto single crystal cds subjected to a variety of surface treatments, are investigated in the ebic mode in a scanning electron microscope. the changes in the contrast observed when the polarity of the applied bias is changed are explained in terms of the penetration of the incident beam, and the..

the surface composition and energetics of type hm graphite fibers

the surfaces of type hm graphite fibers, both treated (hms) and untreated (hmu), were investigated using low temperature thermal desorption, krypton thermodynamic analysis, ion scattering with positive secondary ion mass spectroscopy and contact angle polar/dispersion analysis techniques. the surface energetics of hm fibers increased with..

effect of surface treatment on the properties of carbon fibers and plastic materials based on them

the authors studied the effect of thermal oxidation in air on the properties of high modulus carbon fibers and their epoxy phenol reinforced composites. properties studied include tensile strength, elastic modulus, specific surface, and concentration of paramagnetic centres

fabrication of spectrally selective surfaces by thermal treatment of austenitic stainless steel aisi 321

a technique for obtaining a spectrally selective surface, suitable for the flat-plate collection of solar radiation is described. this involves a simple thermal treatment of the stainless steel under controlled conditions of temperature and time and promises to produce durable selective finishes at possibly lower cost than the chemical co..