Types Of Finishes Research Articles

Assessment of Ni/Pd/Au–Pd and Ni/Pd/Au–Ag Preplated Leadframe Packages Subject to Electrochemical Migration and Mixed Flowing Gas Tests

Preplated leadframes packages with a new noble metal finish type were exposed to various electrochemical migration tests, and mixed flowing gas environments to assess the quality and reliability due to these environmental conditions. Packages were tested as discrete parts and also as parts mounted onto printed circuit boards to assess the effect of reflow soldering. Selected packages with SnPb plated leadframes were tested for comparison purposes. After test exposure, optical microscopy, scanning electron microscope, and energy dispersive spectroscopy analyses were conducted to evaluate the corrosion behavior. Corrosion and creep corrosion on the leads were observed on all the preplated test samples subject to the mixed flowing gas. Creep corrosion over the mold compound surface was identified on the unmounted quad flat no-lead packages. The creep corrosion products were found to be electrically conductive and could bridge adjacent lead pairs

Image Quality of InkJet Printing on Polyester Fabrics

This paper is concerned with the image quality of lines that were inkjet printed on polyester woven fabric. Lines (ideal width of 0.1 mm) running in the warp and filling directions were inkjet printed on different fabrics, and print quality (line width, edge blurriness and edge raggedness) was assessed. The effects of fabric structural parameters (including fabric, yarn and fiber parameters), finishing (type and pick-up), and ink type on line image quality are discussed. Image quality depended on fabric construction, particularly for unfinished fabrics. The satin fabric had the worst image quality while the image quality on the plain fabric was best. Finishing can improve image quality; however, the type of finish was very important. Acrylic resin finish improved printing quality significantly, but results with polyurethane resin-finished fabric were not much better than for unfinished fabric. A volatile ink reduced wicking and improves line image quality; thus, image quality using the alcohol base ink was better than for the oil or glycol based inks.

わが国戦前期の都市独立住宅における外部意匠の変容過程に関する一考察 : 「あめりか屋」の住宅作品の外部意匠を中心に

We analyzed the exterior design of 500 houses designed by Amerikaya housing company that contributed to a development of free-standing urban housing, appeared in the architectural magazines and female magazines in the time period from 1909 to 1943. Analysis points are: exterior wall (finish), roof (shape, material, incline) and window (shape, grille) of the entrance facade showed in the photographs and drawings in the magazines. Analyzing the exterior design allowed us to make the following conclusion. 1) In Meiji and Taisho era, there were three types of finish. In particular, 'wood siding on the first floor and plaster wall on the second floor' 'steep gabled roof' 'square grill in the window' were typical. 2) In early Showa era, particularly after 1932, 'Plaster finish' 'Gently inclined gabled and hipped roof with Spanish tile' were typical. This shift from the former (1909 to 1925) to the latter (1922 to 1940) matched with the styles from Bungalow to Spanish. Both styles were brought from the United States. This study clarified strong influence of American housing on the development of Western style modern urban detached houses in Japan.

Hydrogen Isotope Behavior in Type 316 Stainless Steel Sorbed by Various Methods

Typical materials for components, type 316 stainless steel (316-SS), were chosen as a sample and hydrogen isotope was charged by various methods, water adsorption, electrolysis and ion irradiation to elucidate hydrogen isotope behavior on/in SS. The chemical states of SS surface were studied by XPS and the hydrogen isotope retention and its desorption behavior were analyzed by TDS. Two types of surface finish, namely non-pretreated sample and pretreated sample by polish and annealing were prepared. It was found that the oxy-hydroxide and hydroxide were formed on the surface layer. The hydrogen isotope desorption stages consisted of three stages, namely the desorption stages from oxy-hydroxide, hydroxide and bulk hydrogen. A large amount of deuterium was trapped by the oxy-hydroxide layer for the non-pretreated sample with electrolysis. The hydrogen isotope trapping by this layer would have a large influence on the hydrogen isotope retention. The surface finish would be one of the effective improvement for decreasing its retention on SS.

Fabric design considering the optimisation of seam slippage

PurposeThe dependence of seam slippage values on fabric construction parameters makes this property an interesting case for study.Design/methodology/approachIn this study, made on a significant wool and blended fabrics sample, the seam slippage was measured, either in warp direction (weft yarns slip), or in weft direction (warp yarns slip), using a specially equipped load‐elongation tester. Testing was done following the TM 117 Woolmark Company test method.FindingsFor most fabrics, the conventional variables that impact seam slippage most seriously are opacity, polyamide content, finish type and cover factor.Research limitations/implicationsSince this research does not deal with the variable of yarn crimp in fabrics, it is the cover factor that plays the central role, as the property determining seam slippage. The yarns with lower cover factor (less crimped) are in less danger of slipping between the perpendicular yarns (more crimped) and vice versa.Practical implicationsBased on the equations given, and changing the most relevant variables concerning the explanation of the fabric seam slippage property, the fabric properties can be optimised for specific end‐uses.Originality/valueOptimisation of seam slippage in fabric design.

EFFECT OF SURFACE FINISHES ON THE THICKNESS AND MORPHOLOGY OF THE INTERMETALLIC LAYER IN LEAD-FREE SOLDER JOINTS

One of the most pressing challenges facing today's electronics packaging industry is to identify reliable and cost-effective solder alloys to replace toxic lead containing solder. Besides evaluating new alloy compositions and improving the soldering process, it is important to understand how surface finishes applied to the copper metallization affect the joint characteristics. The characterization of intermetallics during the early stages of nucleation and the growth is hindered by the nanoscopic grain size and layer thickness. This study investigates the impact of PCB finish and solder type on the interfacial intermetallics. Five types of solder and four types of finishes were used: Sn37Pb (SP), Sn3.5Ag (SA), Sn3.5Ag0.7Cu (SAC), Sn2Ag0.5Cu4Bi (SACB) and Sn3Bi8Zn (SBZ) solders, combined with immersion Silver ( I – Ag ), electroless Nickel-immersion Gold (ENIG), Organic Solderability Preservative (OSP) and immersion Tin ( I – Sn ). It was shown that both the SP and SAC solders follow a parabolic growth model and that the surface finish has a significant effect on the intermetallic morphology and growth kinetics. A combined SEM and XRD investigation was shown to be a suitable method for characterizing nanoscale intermetallics.

Evaluation of Three Chemical Protective Clothing Materials for Selected Performance Properties

Abstract A study was conducted to evaluate selected properties of three different chemical protective clothing materials that are being considered for use by Dupont's DeLisle Site in Pass Christian, Mississippi for titanium chloride and related chemical service. Two of the materials represented new product offerings based on unique PTFE/fabric (HSF) laminates, while the third was a PVC/Nomex material currently used in chemical protective clothing at the Dupont DeLisle Site. The two PTFE/fabric laminates were further distinguished by the film thickness and type of surface finish. A number of tests were performed to measure permeation resistance against specific chemicals of interest: physical property testing to assess material strength and specialized tests to determine how the materials hold up to different environmental challenges (high temperature, cold temperature, and flame exposure). The study demonstrated how a series of test methods established by Committee F23 can be used to evaluate the material choices effectively for a specific set of chemical and physical exposure conditions.

Effect of granite dust on the performance charactristics of kernelrazzo floor finish

This study is part of an on-going research on the durability performance of kernelrazzo, a type of terrazzo floor finish. It investigated the effect of partial replacement of the coarse aggregate with granite dust on the compressive strength, water absorption capacity and density of kernelrazzo. Two mix ratios (1:3 and 1:4), varying aggregate replacements of marble chipping with burnt palm kernel shells amounting to 0%, 25%, 50%, 75% and 100%, varying percentage replacements of all coarse aggregates with granite dust amounting to 0%, 10%, 30% and 50% were used. Cost comparisons were also made. Test results showed that the compressive strength of kernelrazzo increases up to a maximum of 30% coarse aggregate replacement by granite dust for both mixes for 0–50% replacement of marble chippings with palm kernel shells. For 75–100% marble chippings replacement, the compressive strength increases with increasing amount of granite dust. The water absorption capacity and density (upto 30% of granite dust) decrease and increase, respectively, with increase in percentage of granite dust. The cost of kernelrazo decreases with increase in the percentage of replacement of coarse aggregates with granite dust, except for 100% marble chipping replacement. It was recommended that to produce a good kernelrazzo floor finish in terms of strength, durability, density, water absorption capacity and cost, the overall coarse aggregate should not contain more than 50% of palm kernel shells for 1:4 and 1:3 mix ratios with a maximum of 30% aggregate replacement with granite dust.

Surface treatment of granite by high power diode laser

Granite stones have been used from times immemorial as structural element for public works and construction of every kind of building. At present, granite stones are used widely for façades, paving and flooring; polished being the most commonly used surface finish type. Recent years have seen a dramatic increase in the demand of granite plates having a rougher, more “rustic” surface finish. In this article we present the results of an exploratory study on the capabilities of the high power diode laser to treat the surface of granite plates. The results allow us to affirm that the laser presents several advantages in comparison to the conventional mechanical method: mechanical stresses are not induced in the granite plate, waste powder is reduced, and hazardous noise is not a byproduct.

Effect of simulated rainfall and weathering on release of preservative elements from CCA treated wood.

The release of arsenic from wood pressure-treated with chromated copper arsenate (CCA) can be decreased by application of wood finishes, but little is known about the types of finishes that are best suited for this purpose. This study evaluated the effects of finish water repellent content and ultraviolet (UV) radiation on the release of arsenic, copper, and chromium from CCA-treated wood exposed to simulated rainfall. Deck boards treated with CCA were either left unfinished or dipped in a finish prepared with 1%, 3%, or 5% water repellent. All specimens were exposed to leaching from simulated rainfall, and a subset of specimens was also exposed to UV radiation. The rainfall was collected and analyzed for total elemental arsenic, copper, and chromium. The water repellent significantly decreased the amounts of these elements in the runoff, but for the short duration of this study there was no difference among the three water repellent concentrations. It is possible that water repellent content would have a greater effect over a longer exposure period. Exposure to UV radiation caused a significant increase in leaching from both finished and unfinished specimens. This effect may be a result of increased surface area during weathering as well as loss of fibers caused by UV-induced surface erosion.

Importance of initial surface film in the degradation of stainless steels by atmospheric exposure

The surface compositions of stainless steels types 304, 316, 430, and 444 combined with four types of surface finishes, 2B finish, hairline polishing, mirror polishing, and bright annealing, were measured by ICP-AES, EPMA, and XPS before exposure. The surface finish that most enriched the chromic species in the surface film was mirror polishing, followed by bright annealing, 2B finish, and hairline polishing. The order of corrosion-resistance was type 444, type 316, type 304, and type 430. The surface compositions were correlated with the rating number and pitting depth after exposure to atmospheric environments. The rating number had a high positive correlation with the concentration of Cr in the surface film, and had a slight correlation with the near-surface composition measured by EPMA at 12 kV, but did not show any correlation with bulk composition within the composition range covered in the present work. This same trend was observed for pitting depth. It was concluded that the cationic concentration of Cr in the surface film before atmospheric exposure is the prime factor in controlling the resistance of stainless steels to atmospheric corrosion.

Comparison of surface sampling methods and cleanability assessment of stainless steel surfaces subjected or not to shot peening

The cleanability of AISI 304 stainless steel surfaces, indicated by the removal of Escherichia coli cells or Aspergillus niger spores was assessed by controlled inoculation and washing treatment of samples in standardised conditions. Two systems of recapture (Rodac plate technique and swabbing technique) were compared. Four industrial finishes, subjected or not to shot peening, contaminated at low concentration (1–10 cfu/cm 2), and then washed with distilled water or alkaline detergent, were examined. The Rodac plate technique detected most of microorganisms inoculated (80% for E. coli cells and 67% for A. niger spores), whereas the swabbing technique recovered only 1% of the E. coli cells and 26% of the A. niger spores. Using the Rodac plate technique E. coli cells proved to be easily detachable from samples either with distilled water (98%) or alkaline detergent (>99%). For the surfaces contaminated with A. niger spores, the cleanability increased from 34% with distilled water to 77% with alkaline detergent. In these working conditions type of finish (shot treated or not) had no significant effect on cleanability of stainless steel.

Soybean oil modified polyesteramide resins

Polyesteramide resin based on the condensation of hydroxyethylamide derivatives of fatty acids of soybean {N, N′‐bis(2 hydroxyethyl)soybean amide} and various dibasic acid and anhydride were synthesized. Physico‐chemical characteristics and film forming properties of these resins were determined to prove its suitability as a vehicle for surface coatings. The study reveals that resins can be used for the baked type of finishes.

Lens Epithelial Cell Migration between Posterior Capsule and Intraocular Lens with Variously Finished Posterior Optic Edge and Two Haptic Angulations

Purpose: To compare lens epithelial cell migration between intraocular lens (IOL) optics and the posterior capsule of IOLs with various edges and haptic angulations. Methods: Experimental acrylic IOLs with 3 types of finishing (none, polishing, tumbling and polishing) and 2 types of haptic angulation (10 and 15°) as well as 3 (AcrySof^® MA30BA, Sensar^® AR40, CeeOn^® 911) clinically implanted IOLs were inserted in rabbit eyes. Scanning electron-microscopic examination of IOLs was carried out before surgery and histological examination of lens capsules 3 weeks after surgery. The grading of lens epithelial cell migration under the IOL was made by scoring. Results: Scanning electron-microscopic examination showed that the optic edge sharpness decreased according to the finishing in experimental IOLs. The AcrySof and CeeOn lenses had sharp edges and the Sensar had a rounded edge. The migration score was highest in the IOL with a rounded edge whereas it was lowest in IOLs with a sharp edge and large haptic angulation. There was no significant difference between the scores of clinically implanted IOLs. Conclusion: Sharpness of the optic edge may be a critical factor for the prevention of posterior capsule opacification and more important than haptic angulation in acrylic IOLs.

The influence of heat treatment and finishing on the mechanical and dielectric properties of glass fabric-epoxy resin laminar composites

The aim of this investigation was to define the optimum conditions of obtaining glass fabric-epoxy resin laminar composites with mechanical and dielectric properties that satisfy the quality needed for production of printed circuit boards for microelectronics. Commercial materials: glass woven fabric, different types of silane finish and epoxy resin were the starting materials in obtaining composites. The conditions needed for the thermal removal of the original size from glass fabric were investigated. The optimal heat treatment should be performed at temperatures less than 550 °C, while cooling rates should be as low as possible. In this manner, the fabric has less than 0.1% of residual size, and the mechanical properties remain satisfactory. Different types of adhesion promoters based on silanes were applied on heat-treated glass fabric as finishes. The quality of the composite material made of thermally and chemically treated glass fabric and epoxy resin was controled by measuring the tensile and dielectric strength of the composite. Depending on which properties of composite are of primary concern, mechanical or dielectric, a finish with an amino functional group and lower heat-treatment temperature or epoxy-modified coatings and higher heat-treatment temperature should be used for obtaining glass-fabric epoxy resin laminar composites.

Effects of Surface Micro-Geometry on the Pressures and Internal Stresses of Pure Rolling EHL Contacts

A fast approach for the calculation of 3-D pressures and subsurface stresses in pure rolling EHL contacts with real (measured) roughness is presented. For the calculation of pressures the model uses the analytical work of Greenwood and Morales-Espejel for transverse (to the rolling direction) moving sinusoidal waviness. The model is extended to handle longitudinal waviness as well. By using these two basic components the pressure distribution for real rough surfaces can now be calculated form the 3-D roughness map. From the surface pressures, the sub-surface stress field can then be calculated with a similar technique. The result is the total Stress State in a rolling rough EHL contact. In this paper the method for calculating the pressures and stress fields is first described. It is then applied to several types of surface finish. Presented as a Society of Tribologists and Lubrication Engineers Paper at the ASME/STLE Tribology Conference in Cancun, Mexico October 27–30, 2002

High performance: Low VOC-content: Innovative and trend-setting coating systems for industrial applications

This paper describes low VOC coating systems successfully implemented and operating in two industrial branches. For Light Alloy Wheels, the innovative coating process comprises ecofriendly chromium-free surface pre-treatment, epoxy polyester powder primer, water-borne base coat and acrylate powder clear coat. The coating process as an example for agricultural machinery includes iron phosphatizing surface pre-treatment for steel substrates; the coating system itself consists of a water-borne stove-type dip priming operation (for all objects). Finish coat type (Plant I): 2-component water-borne PUR top coat; (Plant II): TGIC-free polyester powder top coat. These new coating systems have proved successful in existing series production. All technical requirements and the provisions of the VOC Regulations are fully complied with.

Evaluation of the Environmental Awareness in the Different Types of Metal Finishing in Alexandria

Evaluation of the Environmental Awareness in the Different Types of Metal Finishing in Alexandria

Correlation between Corrosion Potential and Pitting Potential for AISI 304L Austenitic Stainless Steel in 3.5% NaCl Aqueous Solution

We investigated the effect of surface finish of two AISI 304L (UNS S30403) stainless steels on the corrosion potential (Ecorr) in 3.5% NaCl aqueous solution and its value was compared with the pitting potential (Ep) value and the type of anodic potentiodynamic curve obtained for determination of Ep in this solution. Five different surface finishes were examined. Ecorr and its standard deviation are strongly affected by the type of surface finish. Moreover, there are evidences of a linear correlation between Ecorr and Ep, as well as between the percentage of anodic curves with a well-defined pitting potential and the uncertainty in the determination of Ecorr.

Influence of the Surface Topography of Stainless Steel on Bacterial Adhesion

Bacterial adhesion on stainless steel may cause problems such as microbially induced corrosion or represent a chronic source of microbial contamination. The investigation focussed on how the extent and patterns of four bacterial species comprising three different phyla and a broad variety of physicochemical characteristics was influenced by the surface topography of AISI 304 stainless steel. Five types of surface finish corresponding to roughness values R a between 0.03 and 0.89 w m were produced. Adhesion of all four bacteria was minimal at R a =0.16 w m, whereas smoother and rougher surfaces gave rise to more adhesion. This surface exhibited parallel scratches of 0.7 w m, in which a high proportion of bacteria of three of the strains aligned. Reduced overall adhesion was attributed to unfavorable interactions between this surface and bacteria oriented other than parallel to the scratches. Interaction energy calculations and considerations of micro-geometry confirmed this mechanism. Rougher surfaces exhibiting wider scratches allowed a higher fraction of bacteria to adhere in other orientations, whereas the orientation of cells adhered to the smoothest surface was completely random.