Tin-nickel Alloy Research Articles

Time dependence of the chemical composition of the surface film on the metastable tin-nickel alloy studied with X-ray photoelectron spectroscopy. (USA)

Time dependence of the chemical composition of the surface film on the metastable tin-nickel alloy studied with X-ray photoelectron spectroscopy. (USA)

Oxide films on sputtered tin-nickel alloy exposed to pure oxygen and air

Oxide films on sputtered tin-nickel alloy exposed to pure oxygen and air

A Study on Electrolytic Tin-Nickel Alloy Plating from Fluoride Bath

A Study on Electrolytic Tin-Nickel Alloy Plating from Fluoride Bath

Intermetallic Growth and Contact Resistance of Tin Contacts After Aging

The microstructure and the X-ray diffraction properties were studied for tin electroplates deposited from bright acid baths as well as from a stannate bath. Aging at 50°C for 7 years, largely converted 5µm coatings to various intermetallic compounds: Cu <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</inf> Sn <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</inf> and Cu <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> Sn or Ni <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> Sn <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf> depending on the substrate. Dull tin electroplates showed low contact resistance also after aging in spite of a large proportion intermetallic phase at the surface. Bright tin from acid sulphate baths of three different formulations and in particular a tin-nickel alloy coating showed high contact resistances after aging. It seems very doubtful that bright tin could replace gold. Dull tin or tin-lead may offer better chances.

Tin-nickel-plated aluminium bronze dentures.

Nikalium has been found a suitable partial denture base material, except that it has a tendency to corrode in the oral environment. The use of a tin-nickel alloy as a protective coating for Nikalium partial dentures is described. The mechanical suitability of the electrodeposit for this application and its resistance to intra-oral corrosion have been assessed.

Ferritic transformation of an austenitic stainless steel by hot dipping in liquid tin or tin-nickel alloys

By hot dipping 18-10 stainless steel into liquid tin at high temperatures (900–1150°C), there is a superficial ferritic transformation. Nickel additions to the liquid produce changes in the nucleation and growth kinetics and modification of the α phase morphology. The kinetics are controlled by diffusion of nickel at low temperatures and by diffusion of tin at higher temperatures. Discontinuities appear in the temperature dependence of the growth rate, corresponding to a change in the corrosion rate or the disappearance of tin-nickel compounds.

Oxide Films on 1:1 Nickel-Tin Alloy

THE oxide films that provide the corrosion resistance of many alloys are probably salt-like and glassy1–3: more than one metal is found in them and they are frequently structureless by electron diffraction. As part of a general programme to characterize such oxides, we have examined oxide films on the electrodeposited nickel-tin alloy NiSn by Auger spectroscopy and, for comparison, have prepared nickel-tin hydrous oxides by chemical methods. Clarke and his coworkers4–6 have shown that NiSn is very corrosion-resistant to and very readily passivated in, near neutral and moderately acid solutions.

Prediction of metal distribution in electroplating systems

Three methods of approximation were developed to predict the metal distribution in electroplating systems. The results were compared with Watson's experimental data for the Watts-nickel (close to 100% current efficiency), tin-nickel (alloy deposition, also close to 100% current efficiency), and the standard chromium (approximately 20% current efficiency) systems. Method 1 predicted too uniform a distribution whereas Methods 2 and 3 showed good agreements with all three systems. The same experimental data were also used to evaluate three predictive methods frequently used in the literature. The primary current distribution and an empirical formula by Hull were found to be inadequate in describing these systems. The secondary current distribution which involved a great deal of numerical analysis showed a considerable improvement.

スズーコバルト合金メッキについて

The tin-nickel deposit is composed of about 65% of tin and 35% of nickel. It has high resistance to corrosion and tarnish, but is considerably brittle and easily cracked on bending. Such an imperfection of the tin-nickel alloy was not improved by the amendment of the composition of the plating bath.Then, the tin-cobalt alloy deposit was pursued, instead of the tin-nickel alloy. A deposited layer composed of 75-80% of tin and 25-20% of cobalt was steadily obtained from the bath containing 50g/l of stannous fluoride, 20g/l of sodium bifluoride, and 500g/l of cobalt chloride.The plating conditions were as follows.Temperature of bath: 65-80°C Current density: 0.5-4amp./dm2 pH: 2.0The effects of operating conditions and the bath composition on the deposit composition and cathodic current efficiency were investigated. For example, the current efficiency was above 90% for pH=2.0 at 70°C and under the current density of 2.0amp./dm2. On addition of a brightner, the thickness of the deposit allowable was 100μ at maximum, and the electrolyte was stable for prolonged use. The deposit was similar to chrome plating in appearance. Moreover, it had high resistance to corrosion and tarnish, and was not so brittle as the tin-nickel alloy plating.

Metallic phases and activities of nickel-tin-silica catalysts: Dehydrogenation of cyclohexanone, cyclohexanol, and cyclohexane

Addition of tin to a nickel-silica catalyst greatly promotes the activity and gives a longer catalyst life for the dehydrogenation of cyclohexanone and/or cyclohexanol to phenol. Outstanding results are obtained with a catalyst having a nickel-to-tin molar ratio of 2.5:1. Reduction of the nickel-to-tin molar ratio to 0.9:1 gives very little dehydrogenation of cyclohexanone; however, a new reaction takes place, which is the aldolization of cyclohexanone to 2-(1-cyclohexenyl)cyclohexanone. An explanation of the promoting effect of tin and the change in reaction selectivity with nickel-to-tin ratio is given. An investigation of the reduced nickel-tin-silica catalysts by X-ray diffraction has revealed the presence of a supported nickel-tin alloy phase.

Structure and Thermal Stability of Tin-nickel Alloys Electrodeposited from Acid Baths

SummaryX-ray powder photographs of alloys deposited from three types of acid bath were examined. Wide variation in deposition conditions was needed to cause significant change in alloy composition. An alloy with 31 w/o nickel, or more, was a single phase, intermetallic compound whatever the bath used, and retained the same structure up to 43 w/o nickel, the highest value reached. Alloys with less than 31 w/o nickel were two phase mixtures. The single phase alloys increase in density and in compressive internal stress as the nickel content rises, but without major change of lattice parameters. All the single phase alloys decomposed at 300° C, including those whose composition falls within a single phase region of the nickel-tin equilibrium diagram. The single phase alloy is not, therefore, an extension of a cast phase outside the usual composition limits but a new compound.

Coulometric and Jet Tests for Tin-Nickel Alloy

SummaryElectrolytes have been devised to allow coulometric thickness measurements to be made for tin-nickel alloy deposited on brass, on copper or copper undercoats, or directly on steel. The solution when copper or copper alloy underlies the coating contains NiCl2, SnCl4, HCl, and H3PO4, and for deposits direct on steel contains H2PO4, HCl and (COOH)2. The B N F M R A coulometric gauge may be used for the tests. A solution containing FeCl3, NiCl2, SnCl4, and HCl has been devised for jet testing. At constant temperature, the rate of penetration is constant and penetration times for 1 mil deposits at temperatures between 18° and 35°C are given, but the figures for temperatures above 27°C, whilst obtained with care, should be treated with caution. Both methods described should be capable of measuring thickness from 0·1 mil upwards with an accuracy of ± 10 per cent or better and offer advantages in speed and convenience over methods presently recommended, for routine quality control.

Porosity in Single and Multi-layer Electrodeposits, and its Relation to the Basis Metal State

SummaryUsing a quantitative porosity test described previously, it has been possible to study a rather wider range of deposits and basis metals than usual, and thus to draw more general conclusions. Further results are given on the finding that, for strip substrates, a major factor influencing porosity is the depth of substrate surface removed during basis metal pretreatment. Zoning effects have been found in brass and copper strip. An extremely thin surface layer (~ 108 in) on cold rolled steel, can, despite its shallowness, and removal by annealing at temperatures as low as 200°C, exert an enormous influence on porosity in deposits as thick as 2 mil. It can also greatly affect the specular reflectivity of bright deposits. The zoning effects in steel persist through a variety of undercoats and topcoats which have been studied, though in some cases undercoats greatly reduce porosity. The effects also persist through deposits which have been brightened by momentary melting. For the quantitative porosity test, conditions have been found for testing gold electrodeposits on copper. A complementary visual porosity test has also been developed using SO2 atmospheres. Preliminary results obtained with them are given. Gold porosity is affected by zoning in copper foil. Plating current density affects porosity in two gold baths studied; one, an acid bath based on citric acid buffers, generally gave less porous deposits than a cold, alkaline bright bath. A new method of application of electrodeposits is described which can markedly reduce porosity. The electrodeposits used in these studies were nickel, tin, copper, gold, tin-nickel alloy, bronze, speculum (tin-copper alloy), in many cases from different types of bath.

Solderability of Coatings for Printed Circuits

SummarySolderability of a selection of coatings on copper foil, stored under various conditions, has been determined using both the minimum wetting-time test and area of spread tests. Pure tin and tin-lead alloy plated coatings about 0·3 mils thick withstand all the storage treatments with no loss in solderability. A flash of gold over the same thickness of tin-nickel alloy plating was next in order of merit. 0·2 mils of various alloy gold coatings lost solderability under some conditions but in any case caused embrittlement of the solder, thus confirming other work. A brittle bond was also obtained with a thick palladium coating. All of the very thin metallic coatings, the lacquer film and the chemical preservative treatment, allowed a serious loss of solderability during storage. The results are considered to be of direct application in the electronic industry, especially in the field of printed circuitry and it is suggested that the wetting-time test gives the most accurate assessment of solderability ...

Passivity of electrodeposited tin-nickel alloy and other intermetallic tin compounds

Electrodeposited SnNi immersed in aqueous solutions forms a thin protective oxide film which is stable over a wide range of pH and potential. The formation of the film is accompanied by a marked rise in corrosion potential. As an anode SnNi is passive except in HCl and in certain electrolyte solutions from which it may be electrodeposited. A sufficient increase in the applied anode potential leads to the formation of a higher oxide which has good electronic conductivity, and to the evolution of O 2. Anode corrosion during O 2 evolution is negligible except in chlorides. Two compounds with structures similar to SnNi: FeSn 2 and Cu 6Sn 5, also display strong tendencies to form protective films accompanied by a marked rise in potential in the absence of applied potentials. This has an important bearing on the corrosion of tinplate and tinned copper, where these alloys occur as intermediate layers.

Internal Stress in Electrodeposited Tin-Nickel Alloy

SYNOPSISMeasurements have been made of the internal stress in deposits of tin-nickel alloy. The method of Brenner and Senderoff was used. The alloy can be deposited over a range of 36,000 lb/in2 tensile to 40,000 lb/in2 compressive stress. The factors affecting stress are plating bath temperature, current density and chloride content. The change from tensile to compressive stress, brought about by either raising the bath temperature or adding choride, is in both cases accompanied by a small increase in the nickel content of the deposit. When plated on flat panels of steel, the deposit tends to crack when the stress exceeds 7,000 lb/in2 tensile. Examination of the effect of chloride suggests that deposition occurs from a complex ion of the type (NiSnF4Cl2)--, in chloride-fluoride solutions and from (NiSnF6)-- in all-fluoride solutions. A simple equation relates stress, bath temperature and current density in an all-fluoride electrolyte. For certain applications, it is recommended that, in making up a bath ...

Corrosion Prevention in Automobile Bodies

The prevention of corrosion in car bodies has reached a high degree of excellence, or still leaves much to be desired, according to the point of view adopted. The organic finishing of the main part of car bodywork, utilizing heavy undercoats and durable top-coats on steel often prepared by phosphating, has reached a very satisfactory degree of excellence on flat or nearly flat surfaces. Difficulties still arise at edges, corners, crevices and re-entrants. These are discussed in relation to general principles of design and of testing. The finishing of trim is in a more fluid condition. Nickel/chromium plating of steel, zinc-base alloys and brass has long been the general bright finish adopted. The relative advantages and disadvantages of such trim and that made from bright anodized aluminium and from stainless steel are discussed. Newer finishes such as electrodeposited nickel-tin alloy coatings are also considered. Temporary corrosion prevention, such as can be applied to finished bodies for the period after manufacture but before service, is described. The contribution to corrosion prevention that can and should be made by the user is outlined. Storage methods vary widely, but are a very important factor in the life of a car. Cleaning and polishing methods are discussed. The general principles of corrosion testing appropriate to car bodies are considered, in the light of the very varied corrosive environments that are experienced in service.

ニッケル・スズ合金電極のアルカリ溶液における水素過電圧および酸素過電圧

ニッケル・スズ合金電極のアルカリ溶液における水素過電圧および酸素過電圧

Ni-Sn合金の時効硬化について

Ni-Sn合金の時効硬化について

Further tests on the stability of analytical weights in chemical laboratories

The stability, in the corrosive atmospheres of chemical laboratories, of brass weights coated electrolytically with nominal thicknesses of 13 μ and 25 μ of tin-nickel alloy (65% Sn, 35% Ni) has been compared with that of weights previously tested(1) under similar conditions. As regards appearance after exposure, the 25 μ coating was the best, and was comparable with weights of highly-polished stainless steel save in the severest conditions. All the alloy-coated weights showed about the same stability of mass as good quality commercially produced weights of austenitic stainless steel (25% Cr, 20% Ni) and rhodium-plated brass weights. Tin-nickel alloy plating does not possess any undesirable magnetic properties. In highly corrosive atmospheres, non-magnetic nickel-chromium (80% Ni, 20% Cr) is a little less resistant than the materials already mentioned. Of the small sheet metal weights of various materials tested, those of austenitic stainless steel were definitely the best. They were followed, in order of merit, by zirconium, tantalum and aluminium, and finally, titanium.