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To improve the bonding strength between the nickel bond and the hub of the electroplated diamond grinding wheel, a hybrid technique was proposed to combine laser pre-quenching steel substrate and post-electroplating nickel. To validate the effectiveness of the proposed technique, AISI 1045 substrate was nickel-coated. The bonding properties between the electroplated nickel coating and substrate with or without laser-discrete-quenching were discussed comparatively by scratch, indentation, and thermal shock tests. The results show that the pre-quenching treatment leads to phase transformation of AISI 1045 microstructure from the mixed pearlite and ferrite phases into the martensitic phase. Since the martensitic phase is characterized as a high corrosion resistance, the interface of substrate/coating is smooth and flat in the pre-quenched zone, and the coating is bonded well with the steel substrate. In contrast to the steel substrate without pre-quenching treatment, the proposed technique significantly enhanced the bonding strengths of the electroplated nickel-coating. On one hand, the average hardness of electroplated nickel-coating on the laser pre-quenched zone is increased by 18.7%, and the scratch depth with the same load become narrower and shallower. On the other hand, the coefficient of friction (CoF) and the vibration amplitude are reduced, and the coating is bonded effectively with the substrate to inhibit the crack initialization at the interface. This prevents effectively the coating from peeling off and improves significantly the thermal shock resistance property.

The most important significant renewable energy for power production is solar radiation. In solar products emissivity of the material used create more impact on performance. So this investigation study about the emissivity of black nickel coated stainless steel surfaces by varying the thickness of the coating. In this study three different thickness of coating are considered for investigating such as 0.2 mm, 0.3 mm and 0.4 mm of black nickel coating. In each thickness have three different heats such as 150 W, 180 W and 210 W are the input for identification of surface temperature of the black body and black nickel coated body.

The purpose of this work is to examine the microstructure, mechanical and sand abrasive properties of friction stir welded joints of aluminium alloy AA6061-T6 with and without nickel coating. A total eighteen samples, six samples of AA6061-T6 plates, six samples of 10 μm thick Ni coated AA6061-T6 plates and six samples of 15 μm thick Ni coated AA6061-T6 plates were friction stir welded by using different tool rotation speed (710 rpm, 1000 rpm, 1400 rpm) and different welding speed (28 mm/min, 56 mm/min). The joints manufactured using 1400 rpm tool rotation speed and 56 mm/min welding speed generated the highest tensile strength and percent elongation with joint efficiency of 69.05% with 15 μm Ni-coated AA6061-T6 plates and joints manufactured from 10 μm Ni-coated AA6061-T6 plates using 1000 rpm tool rotation speed and 28 mm/min welding speed generated the highest impact energy and higher hardness in NZ compared to the other joints. The 15 μm Ni-coated AA6061-T6 plates exhibited better abrasive wear resistant properties than the 10 15 μm Ni-coated plates. Microstructure investigation showed the precipitate size variations and their distributions and after friction stir welding, these precipitates became slightly coarser in the HAZ but finer in the nugget region.

The development of electroless coatings on various substrates has gained much interest among researchers for the sake of improved properties. However, the coating on ceramic particles as a source of reinforcement is still a challenge for the researchers and requires a good comprehension of fundamentals since the coating thickness relies upon many parameters. Particularly the sensitization and activation conditions are more important for the creation of an ideal environment to draw metallic ions as a coating layer. Therefore, this paper examines the role of sensitization and activation conditions on the viability of nickel coating on the alumina particles of an average size of 50 nm. A comparison is made between two environments, namely individual and blended activations in the preparation of coated particles. Characterization studies are also presented to support the discussion.

The aim of this work is to understand the effect of a thin coating on the compressive properties of the porous metal. In our work, the uniaxial compressive behavior and the energy absorption properties of the lotus-type porous copper deposited with Ni coatings with thickness from 3.9 to 4.8 μm on pore walls were investigated. It is found that the Ni coating on pore walls shows a clear enhancement effect on compressive properties of the lotus-type porous copper, in which the specific yield strength and the energy absorption per unit mass at densification strain increase from 5.27 to 7.31 MPa cm3 g−1 and from 11.50 to 18.21 J g-1 with the Ni coating, respectively. Furthermore, the enhancement appears to be insensitive to the coating thickness. It is considered that the resistance of the interface between the nickel coating and the pore walls to the dislocation slip plays an important role in the improvement on compressive properties of the lotus-type porous copper.

A scanning electrodeposition technology was proposed to fabricate superhydrophobic nickel coating. The microstructure, the surface chemical composition, and the wettability of the coating were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and contact angle-measuring device. The SEM images showed that there were cauliflower-like clusters on the coating surface, which were attributed to the “tip effect”. The newly prepared coating was not superhydrophobic, but after exposed to air for one week, the contact angle of a 6 μL water droplet on the surface reached 155.4° and the sliding angle was only 6.5°. The XPS analyses indicated that this phenomenon was due to the adsorption of organic compounds from the air. This method has potential for practical applications, as it is flexible and controllable, simple and fast, and the prepared coating showed an excellent superhydrophobic property.

This paper deals with the effect of electrodeposited zinc and nickel coatings on the fatigue strength of a free cutting steel. This class of materials is frequently used in the mass production, due to their good machinability, in order to reduce the production costs. Moreover, free cutting steels often operate under high wear conditions, for instance in sliding components. Therefore, suitable coatings are usually applied to improve their tribological response. In addition, in many industrial applications, free cutting steels must withstand significantly high fatigue loads, even in corrosive environment. In order to assess the fatigue response, S–N curves and endurance limits at run-out of specimen sets with different features were determined. The tests involved samples with different coatings and plain geometry for comparison purposes. The experimental results, properly set up by tools of Design of Experiment, were statistically processed and compared. The outcome was that no significant difference in terms of fatigue strength between the three specimens set was encountered. It implies that coatings can be suitable to enhance wear resistance without detrimental effects on fatigue.

In order to lengthen the lifespan of NdFeB materials, nickel coating was manufactured by magnetic jet electrodeposition. The surface morphology, coating adhesion, and corrosion resistance of the co...

The limited quantity of raw materials leads to application-optimised materials, such as open-cell hybrid foams. A nanocrystalline nickel coating significantly enhances the crash absorber properties of aluminum and PU foams with only a small increase in weight. The coating is applied by an electrodeposition process. Due to mass transport limitations during the process, an inhomogeneous coating thickness is created resulting in inhomogeneous material properties. To avoid different coating thicknesses at different points of the foam, the electrodeposition process in the foam is modelled and simulated. The results of the simulation are compared with experimental data and the influence of different parameters on the coating homogeneity is investigated by means of simulation.

Using tungsten, carbon, and nickel powder as raw materials, an in situ synthesised WC reinforced nickel matrix (marked as IWC) coating was fabricated on a mild steel by laser cladding. The experime...

Nickel coating on zinc alloy is quite promising for the achievement of an additional wear improvement in corrosive environment. To investigate this point, block-on-ring tests were carried out. Blocks measuring 5 × 5×20 mm3 were obtained from real locking components, made of ZP5 EN 12844 and coated by Zn/Cu1Ni5s ISO 1458. As counter material, an AISI 304 with a 40 mm diameter cylindrical geometry was used. Three load levels (5, 10 and 15 N) and three coating thickness levels (low: 5 to 10 µm; medium: 10 to 15 µm; high: 15 to 20 µm) were considered. The sliding distance was initially set to 500 m. Then, since the coating was worn out very quickly during the test, the sliding distance was set to 150 m. The results, in terms of volume loss due to wear, were processed using the statistical tool of two-way ANOVA and Fisher test. It was assessed that the wear rate is strongly affected by the applied load. The coating thickness does not significantly affect the wear.

This study aimed to investigate the effects of temperature, load and frequency on the wear and friction behaviour of the cast iron and nickel-coated tribosurface on mild steel. The experiments were performed at three different levels of loads (10, 20, 30 N), frequency (24, 30, 36 Strokes/s) and temperature (40, 80, 120 ℃) using a linear reciprocating tribometer. An L9 orthogonal array as per the Taguchi technique was used to analyze the specific wear rate (SWR) and coefficient of friction (COF). The coated surface showed better tribological behaviour as compared to cast iron. The temperature had maximum influence on the tribological behaviour followed by load and frequency.

The common occurrence of the phenomenon of cavitation in many industries and the multitude of factors affecting the resistance to cavitation erosion of used materials contribute to the search for methods and appropriate parameters of coating application that are able to minimize the effects of erosion. To determine the validity of the developed application parameters and the method used, cavitation studies and microscopic observations of the development of erosion during the cavitation test were carried out. There was a clear lack of incubation time and a linear increase in losses after 60 min of the test. Moreover, the damage observed during the test overlapped, widening the area of erosion and thus leading to damage to the integrity of the coating.

When developing microscale robotic systems it is desired that they are capable of performing microscale tasks such as small scale manipulation and transport. In this paper, we demonstrate the transport of microscale objects using single or multiple microrobots in low Reynolds number fluidic environment. The microrobot is composed of a ‘U’ shaped SU-8 body, coated on one side with nickel. Once the nickel coating is magnetized, the motion of the microrobots can be driven by external magnetic fields. To invoke different responses from two microrobots under a global magnetic field, two batches of microrobots were fabricated with different thicknesses of nickel coating as a way to promote heterogeneity within the microrobot population. The heterogeneity in magnetic content induces different spatial and temporal responses under the same control input, resulting in differences in movement speed. The nickel coated microstructure is manually controlled through a user interface developed using C++. This paper presents a control strategy to navigate the microrobots by controlling the direction and strength of externally applied magnetic field, as well as orientation of the microrobots based on their polarity. In addition, multiple microrobots are used to perform transport tasks.

A fast, low cost solution route to nickel dot coated NbC powder using Ni(NO3)26H2O, Ni(OAc)24H2O and triethanolamine (TEA) as precursors in methanol solvent was developed. After mixing the precursor solution with 50–300 ​nm sized NbC powder and evaporation of the solvent, heating to 150 ​°C, or higher, yielded NbC powder evenly covered with well-dispersed nickel metal dots, 6–25 ​nm in size, depending on the nickel loading and temperature. Coatings yielding 4 to 14 ​wt% nickel loading were studied at temperatures from 200 to 700 ​°C, using TG-DTA, XRD, SEM, XPS with Ar+-ion etching, TEM/DF, and STEM/HAADF/EDS.

We present a simple technique to fabricate magnetic helical microswimmers with excellent surface quality and swimming performance. These were obtained through depositing a nickel film on the Spirulina biotemplates by electroless nickel plating. The morphology and coating composition of the as-prepared microswimmers were analyzed. Homogeneous and compact nickel coating was successfully deposited on the helical biotemplates, and Ni element could reach ~95wt%. Its magnetic property was also characterized. Moreover, a controlled rotating magnetic field was applied to manipulate such a microswimmer in deionized water. Its motion behavior was further analyzed, indicating that such microswimmers could be actuated and steered precisely at low Reynolds numbers. The magnetic helical microswimmers may have potential biomedical applications such as targeted drug delivery and cell manipulation.

The effect of the thickness of a catalytic nickel coating deposited on a copper substrate by an electrochemical method on the intensity of formation of carbon nanomaterials in the CVD process was investigated. It was found that the dependence of the specific nanostructured carbon yield on the coating thickness is extremal, with a maximum near 1.5 μm. Qualitative interpretation of the obtained data is proposed on the basis of the carbon growth mechanisms on the catalytic coating.

In this paper, the results of measurements of nickel coating thickness are presented. Ni coatings were deposited onto zirconium alloy Zr-1Nb and Si wafers by dc magnetron sputtering. The thickness of Ni coatings was measured by scanning electron microscopy (SEM), ball abrasion method and non-destructive X-ray diffraction (XRD) method. The developed technique of determination of coating uniformity by grazing incidence XRD method was shown. The estimation of uniformity of Ni coatings with a thickness from 0.5 to 2 µm was performed. The distribution map of the coating thickness over surface of 20×20 mm was constructed. The deposited coating with higher thickness of 2 µm has 10% deviation of thickness.In this paper, the results of measurements of nickel coating thickness are presented. Ni coatings were deposited onto zirconium alloy Zr-1Nb and Si wafers by dc magnetron sputtering. The thickness of Ni coatings was measured by scanning electron microscopy (SEM), ball abrasion method and non-destructive X-ray diffraction (XRD) method. The developed technique of determination of coating uniformity by grazing incidence XRD method was shown. The estimation of uniformity of Ni coatings with a thickness from 0.5 to 2 µm was performed. The distribution map of the coating thickness over surface of 20×20 mm was constructed. The deposited coating with higher thickness of 2 µm has 10% deviation of thickness.

With the purpose of decorative bright nickel plating process, nano-nickel and ordinary bright nickel coatings were prepared by applying the electro-deposition method with DC and PRC respectively. The grain sizes, organizational structures and surface morphologies of samples were characterizated by X-ray diffraction(XRD) and scanning electron microscopy (SEM) analysis. The corrosion resistance of the samples were determined by immersion corrosion test, salt spray corrosion test and electrochemical methods. The results showed that the corrosion resistance of reverse pulsed electrodeposition nano-nickel coating is superior to the DC electrodeposition nickel coating.

Long-term strength of alloy EP741NP is studied after standard heat treatment and after process heating in the mode of diffusion joining of protective nickel coating in the production of turbine wheel.

Ni coatings with different grain sizes and preferred orientations were produced by the control of current density during a direct current electrodepositing process. The effects of grain size reduction and preferred orientation on the oxidation behavior in air at 600°C and 960°C of Ni coatings were investigated respectively. An important and interesting result is that after oxidation at 600°C, the Ni coating obtained at lower current density has a better oxidation resistance, whereas after oxidation at 960°C, the Ni coating obtained at higher current density has a more compact scale and a better oxidation resistance. For the Ni coatings oxidation at 600°C, the oxidation behavior was mainly influenced by grain size, whereas in the case of the Ni coatings oxidation at 960°C, the oxidation behavior was only slightly influenced by grain size. The changes in oxidation behavior of Ni coatings at 960°C can be attributed to the different preferred orientation and the corresponding oxidation mechanism.

Possibility of making thinner silver coatings on low-current sliding contacts in deposition of multilayer nickel-silver and copper-nickel-silver coatings from various electrolytes was studied.

To improve the sensing characteristics of a Fiber Bragg grating(FBG) temperature sensor with a Ni coating,the causes of the hysteresis error and the difference of sensitivities when it was heated and cooled were researched.Results indicate that the residual stress induced by electroless-electroplating makes the sensor imprecise.The mechanism of the residual stress was discussed,then a heat treatment method was proposed for the metallized FBG(MFBG) with a nickel coating.In treatment,the MFBG sensor was put in a drying oven at 120 ℃ for 8 hours three times,and every time it was cooled with the oven.A comparison experiment for the MFBG with the nickel coating was performed in 100-300 ℃,results show that the hysteresis error of the sensor is 6.64%,and the difference of sensitivities when it is heated and cooled is more significant before the heat treatment.The sensor characteristics are not be amended even if it is performed temperature cycle again after half a month.However,the hysteresis error of the sensor is descended to 3.62%,and the sensitivities of the MFBG when it is heated and cooled are 22.84 pm/℃ and 22.76 pm/℃,respectively,after the heat treatment.The experiments demonstrate that with a higher sensing accuracy,the working range of the MFBG with the nickel coating has expanded to 300℃ after effective heat treatment.

A novel blister test theory model was developed based on the bending theory of beams for assessing the interface strength of the nickel coating/low carbon steel substrate material system. The strain energy of the debonded nickel coating was calculated analytically and by finite element analysis, respectively. The analytic solutions agree well with the FE calculation results. Some blister tests were carried out on the WII-5 Computer Controlled Material Mechanical Properties Testing Machine, using four nickel-coated specimens type-A, -B, -C and -D which were electrodeposited on low carbon steel substrate. Here, types A, B, C and D correspond to the nickel coating thickness of 5 μm, 10 μm, 15μm and 25μm, respectively. The interface strength, evaluated by this blister test method, is 196.86 J/m2 and 269.40 J/m2 for type-C and -D specimens, respectively. However the tests demonstrate that the type-A and -B specimens were cut through by the spindle and no delaminations between the coating and the substrate could be found.

Copper molds are critical components in the continuous casting of steel. Surface condition of the mold directly affects product quality, and premature failure/low wear life affects the output of the continuous casting plant. This paper presents the failure analysis of a nickel coating on a copper plate during a plant trial using in situ ultrasonic testing for coating thickness evaluation and in situ testing to confirm the loss of coating. The failure analysis indicated maximum coating wear near the bottom corners of the mold. More wear was found on the wide end face compared with that observed on the narrow face. On top portion of the mold, wear was almost negligible. Based on the wear profile obtained during trial, it was recommended that the coating on the bottom portion of the mold have a higher hardness to improve mold life.

The forming limits of nickel coating on the right region were studied, so as to direct the preparation of the material and help the production of workpieces. The electrodeposited nickel coating was prepared on steel substrate to form advanced structures, and its plastic instability was investigated by the Swift Plastic Instability Theory. By using the compound law for laminated sheet metals, explicit equations for the calculation of the instable eigen values were deduced. The forming limit diagrams of the nickel coating on the right region were plotted. It is exhibited that the forming limit of the coating sheet is between the forming limits of the individual nickel coating and steel substrate. The forming limit of the nickel coating is not so good as that of the steel substrate, and the forming limit strain of the coating sheet tends to diminish with the increase of thickness of the coating. The greater the normal anisotropic coefficient of the materials is, the better the forming limit is.

An electroless-nickel plating method with semi-batch reactor was employed to coat diamond powders. Ni–P fines are known to be a main cause for generating pore structure in the nickel coating layer was eliminated by lowering the rate of reduction by means of temperature, pH and feeding rate of reductant. It was found that at a temperature of 70 °C, pH of 4.8, feeding rate of reductant of 0.25 ml/min the Ni–P fines were entirely eliminated, resulting in a rapid improvement of diamond-coated nickel layer adhesion.

Electrochemical polymerization of polyindole (PI) was investigated on nickel-coated mild steel (MS/Ni) electrode in LiClO4 containing acetonitrile medium (ACN-LiClO4). One-micrometer-thick nickel coating was electrodeposited on MS galvanostatically in a proper bath solution. Then, the synthesis of PI film was achieved in 0.2 M indole containing ACN-LiClO4 by using cyclic voltammetry technique. It was proved that the synthesized PI film was very smooth and homogeneous. The corrosion performances of MS/Ni- and PI-top-coated MS/Ni samples were investigated properly in 3.5% NaCl solution. For this aim, electrochemical impedance spectroscopy (EIS), anodic polarization curves and open circuit potential-time (Eocp-t) diagrams were used. The porous nickel coating exhibited a physical barrier property on the surface and provided some protection to MS. But its permeability increased significantly with time and failed to protect MS. It was shown that PI-top-coated Ni coating exhibited much better protection efficiency to MS for considerable periods in such aggressive medium. The polymer film exhibited effective barrier behavior and lowered the permeability against the attack of corrosive environment. © 2004 Elsevier B.V. All rights reserved.

This paper presents results of a research on the corrosion resistance of composite Ni/Al2O3 coatings electrochemically deposited from Watts baths containing different amounts (0, 20, 100 g dm−3) of Al2O3 particles. Potentiodynamic tests and electrochemical impedance spectroscopy (EIS) measurements were carried out in a 3% solution of NaCl. The coatings with about 6 wt-% of corundum, deposited from a bath with 100 g dm−3 of a powder, showed the best protective properties. The rate of corrosion of such coatings after 7 days of exposure in the NaCl solution was over two times slower than that of coatings containing 2 wt-% of Al2O3 and six times slower than that of a standard nickel coating. Two equivalent circuits: one consisting of two RC circuits and the other one made up of three RC circuits were used for the analysis of the impedance spectra. Regardless of the presence and amount of the Al2O3 particles in the nickel coating, during first day of exposure in the NaCl solution a layer of nickel oxid...

Mg2Ni alloy prepared by powder sintering was chemically coated with 10% nickel by weight. The effects of the nickel coating on the surface appearance, the structure of the alloy and the electrode characteristics were investigated. The discharge capacity and cycle life of the nickel-coated alloy electrode were greatly increased in comparison with values for the bare alloy because of the changed phase structure and surface properties.

Acid hypophosphite solution for electroless deposition of a Ni-P alloy containing up to 12 wt % phosphorus was developed and recommended for practical use. The possibility of repeated use of the solution developed was examined.

The paper presents a survey of the current methodology and practice in the control of grinding circuits in industrial ball mills and the methods for renovation of shafts for extruding of sheet material. Modern control strategies applied in the grinding circuit of ball mills are compared and analyzed. Also, different electro-physical and electro-chemical methods for renovation of shafts are discussed and an innovative technology for laying a nickel coating with nano-particles and nano-dispersoids is outlined.

The abrasive wear of nickel coatings on steel substrates, under corrosive conditions was studied. For specimens with and without heat treatment, the wear rate was observed to depend upon the nature of the corrosive solution. The composition of the wear debris was noted to be a function of the corrosive wear conditions. The wear rate of the heat treated specimens was observed to be lower than that of the non-heat treated nickel-coated steel specimens.

In plating and coating applications, prior surface conditions greatly affect the integrity of processing applications. XPS has proved to be a useful tool in the investigation of substrate surfaces. By implementing XPS spectral analysis on various aspects of the plating processes, information on potential conditions, which could affect the system, can be identified. In addition, standards can be used to identify when a process is not within acceptable production limits and can aid in failure investigations. The results of this study have demonstrated that a tool that has traditionally been employed for basic research can effectively be integrated into industrial applications.

The effect of nickel coating upon the torsional behaviors of single-walled carbon nanotube (SWCNT) was defined, and torsion behaviors were investigated using the molecular dynamics (MD) simulation method. In this work, an armchair (6,6) carbon nanotube was considered. Both SWCNT and SCNT coating Ni (SWCNT-Ni) were analyzed at 0K and 300K. By simulating torsion process of SWCNT-Ni, mechanical behaviors of SWCNT-Ni could be defined. When torsion rate was relatively high, it had been reported that the torsional stiffness of SWCNT would reduce even at low temperature. However, to avoid the effect of torsion rate upon mechanical behaviors of SWCNT and SWCNT-Ni, an extremely low torque was applied which was corresponding to low torsion rate, and it was observed that the torsion angle of SWCNT and SWCNT-Ni were almost the same at the initial stage. That was to say, the metal coated atoms had little effect on torsional stiffness at extremely low torsion rate. When temperature rises, the effect of temperature begun to emerge. It was noted that the nickel atoms trended to rearrange, and the nickel atoms were more likely to migrate to the place of great deformation, and the torsion changed the curve of the outside surface, which caused the increase of Ni-C interactions.

The effect of nickel coating on the bending properties of Stereolithography (SL) parts was investigated. It was found that a thin layer of nickel coating significantly improves the flexural strength and modulus of the SL specimens. The strengthening effect of the coating is dependent on the ratio of the Young’s moduli of the coating and the substrate materials, as well as the thickness of the coating.

Supporting the Telescope structure is done via a Bearing Sphere in a Hydraulic bearing which is part of the SOFIA Suspension system. Frictionless bearing requires a sphere with varying stiffness in defined directions and a smooth and wear resistant surface giving also corrosion resistance against humidity and hydraulic fluid. Weight restrictions and through penetration by the Nasmyth Tube required a highly sophisticated design and manufacturing techniques. The 1.2 m sphere is cast from nodular cast iron, machined and coated by electrodeposition with a sulfamate nickel coating on the outer bearing sphere surfaces. The sphere represents a one of a kind construction unique in stiffness to mass ratio. The design as well as manufacturing philosophy of the sphere are presented.

SummaryThe corrosion resistance, hardness, lubricity, wear resistance, solderability, bondability, non-magnetism of high phosphorous-nickel alloy and uniformity of deposit thickness on complex shapes makes electroless nickel ideal for a wide range of applications. These properties of electroless nickel are reviewed.

Superior corrosion resistivity of nickel-chromium coating can be presumed to some extent from the electrochemical investigation previously reported.A series of corrosion tests, including outdoor exposure at seaside, was carried out to study the performance of copper-nickel-chromium and double nickel-chromium plated steel test pannels.As a result, the following conclusions were obtained:(1) In the salt spray and sulfur dioxide test, any superiority of the double nickel-chromium coatings to the copper-nickel-chromium coating was not observed.(2) In the Korrodkote and CASS test, the performance of the former was excellent, regardless of the thickness. On the other hand, the latter was rapidly deteriorated.(3) In the outdoor exposure at seaside, the former with total thickness of 30μ was excellent, but the former with total thickness of 20μ was often inferior to the latter with total thickness of 40μ.(4) As the proportion of semibright nickel in a double nickel coating is increased, its durability in the outdoor exposure increases. Contrary to this, quite reversed phenomenon was observed in the Korrodkote and CASS tests.

SummaryThe deposition of an attractive nickel coating from a reliable easily maintained solution with an all-liquid brightener system is described. It is considered that the versatility of the final product has proved more than worth the little extra plant required in this system for temperature adjustments. The finish has a characteristic sheen which is attractive and recognizable. The method of attaining it has novel features and is interesting both in theory and practice. Its applications in the decorative field of finishing are extremely wide. The finish is also of considerable importance in satisfying the new safety regulations for automobile components.

During the course of a routine orthopaedic surgical procedure, a stainless steel external fixation connecting bar was deliberately bent to accommodate the patient's anatomy. It was found that the bar carried a nickel electrodeposited coating that flaked off the bar surface due to the bending. It is believed that the presence of a nickel coating might cause adverse tissue responses in patients and surgeons should be aware that connecting bars for external fixators might carry such coatings.

Etude experimentale de l'influence d'un depot electrolytique mince de nickel avec une sous-couche de cuivre sur la comportement en fatigue d'un acier au carbone. Essais de fatigue en flexion rotative et examen de la fissuration et de la microdurete des eprouvettes. Observations par microscopie electronique a balayage des facies de rupture.

Resultats d'essais effectues avec divers substrats revetus comprenant des particules de diamant polycristallin dans une matrice de nickel chimique. Ces substrats ont ete mis en contact avec un bain de depot chimique de nickel. On a fait varier l'epaisseur du recouvrement en faisant varier le temps de placage, et on a enregistre la rugosite resultante de la surface. On montre que les particules de diamant ont une tendance catalytique

The fatigue life of nickel-plated copper depends upon the thickness of the nickel coating. Increases in life from 150 to 450 percent were obtained by increasing the thickness of the nickel from 0.0001 to 0.00025 in. (0.00254 to 0.00635 mm). A further increase in thickness to 0.005 in. (0.0127 mm) resulted in an increase in life of 200 percent. Interrupting the current during electroplating produces interfaces within the coating and increases the fatigue life for a given thickness. Increases in life of 110 percent were obtained by applying a 0.0005-in. thick coating in five layers, rather than in a single layer.

The instrument and its various parts are so well shown in the illustrations that no further description is necessary. It is a more powerful instrument than the ordinary tonsil snare and does not get out of order like many others. It is simple in application, can be used a number of times without requiring a new wire, and, if properly adjusted, the wire cannot slip. It should be manipulated by a sort of forearm and wrist movement, instead of by the fingers, in closing it, so that the barrel will not be thrown out of line. It is made of solid brass with a heavy nickel coating. Number 7 or 8 piano wire should be used. I have used the instrument a number of times with excellent results. It is made by the O'Brien Worthen Co., Frisco Building, St. Louis. 220 Metropolitan Building.