Nickel coatings mechanical properties

Sulfur compounds, whether organic or inorganic in nature, cause sulfidation in susceptible materials. The sulfide film, which forms on the surface of much con-stmction materials at low temperatures, becomes friable and melts at higher temperatures. The presence of molten sulfides (especially nickel sulfide) on a metal surface promotes the rapid conversion to metal sulfides at temperatures where these sulfides are thermodynamically stable. High-alloy materials such as 25% Cr, 20% Ni alloys are widely used, but these represent a compromise between sulfidation resistance and mechanical properties. Aluminum and similar diffusion coatings can be of use. 

Deposits from Watts-type solutions Most coatings of nickel for engineering applications are electro deposited from a Watts-type bath Typical mechanical properties of deposits from Watts and sulphamate solutions are compared with those of wrought nickel in Table 13.15. 

A major advantage of the electroless nickel process is that deposition takes place at an almost uniform rate over surfaces of complex shape. Thus, electroless nickel can readily be applied to internal plating of tubes, valves, containers and other parts having deeply undercut surfaces where nickel coating by electrodeposition would be very difficult and costly. The resistance to corrosion of the coatings and their special mechanical properties also offer advantages in many instances where electrodeposited nickel could be applied without difficulty. 

Nickel in Nanometer Materials. Coating a metal with an ultrathin layer of another metal creates properties not found separately in either of the materials. Considerable recent research has been directed toward improving the mechanical properties of bimetallic laminates, sometimes called composition modulatedfilms, which have interlayers only a few nanometers thick. Attractive properties also have been found for similar systems, called nanometer materials. Nickel has been used in combination with copper, ruthenium, and other metals for producing these new materials. 

However, during long exposures to medium-temperature operating conditions, e.g. 1000°C, spinel formation is certainly expected. Wang etal.60 demonstrated this for the Ni-alumina system, showing the diffusion of Ni atoms to the free surface of the nanocomposite, followed by the formation of a nickel spinel surface coating which then limits the kinetics of subsequent oxidation. In this case the formation of a spinel surface layer may be beneficial to mechanical properties, since the reaction results in a volume increase, and the formation of compressive residual stresses. An analogous behavior was reported for ceramic particle nanocomposites, where oxidation of SiC particles results in an increase in volume and compressive residual stresses.61... 

Zvyagintseva A.V., Falytcheva A.Y. (1997) Physico-mechanical properties of nickel-boron coatings, Galvanotechnique and surface treatment 2 (5), 24-31. 

Next-generation metallic biomaterials include porous titanium alloys and porous CoCrMo with elastic moduli that more closely mimic that of human bone nickel-titanium alloys with shape-memory properties for dental braces and medical staples rare earth magnets such as the NdFeB family for dental fixatives and titanium alloys or stainless steel coated with hydroxyapatite for improved bioactivity for bone replacement. The corrosion resistance, biocompatibility, and mechanical properties of many of these materials still must be optimized for example, the toxicity and carcinogenic nature of nickel released from NiTi alloys is a concern. ... 

Besfight MC and HTA-CF - carbon fiber nickel-coated with excellent mechanical properties of carbon fiber and good electric conductivity of nickel. The material for conductive plastics. 

An important category of the surface finishing industry is plating. This includes the process of electroplating which provides metals with surface coatings (usually by electrodeposition) for corrosion protection, wear resistance, improved electrical and mechanical properties, etc. Ferrous and non-ferrous materials can be electroplated with copper, nickel, chromium, zinc, lead, cadmium, etc. They can also be electroplated with precious metals such as gold and silver. 

Over the years, the use of coatings such as HAp for implants and prostheses has gone from being a rarity to being an absolute necessity. A number of excellent studies on adhesion and mechanical properties have been carried out on a range of coatings major ones include HAp, diamond-like carbon (DLC), titanium nitride, titanium oxide, and nickel-titanium (Ben-Nissan et al., 2013). Listed below are some studies carried out on pure HAp and DLC thin films. 

Studies on randomness of filler distribution in polymethylacrylate nanocomposite are interesting. In this experiment, siUca particles were formed both before and after matrix polymerization. The results indicated that the concentration of silica was a controlling factor in the stress-strain relationship rather than the uniformity of particle distribution. Also, there was no anisotropy of mechanical properties regardless of the sequence of filler formation. This outcome cannot be expected to be duplicated in all other systems. For example, when nickel coated fibers were used in an EMI shielding application." When compounded with polycarbonate resin, fibers had a much worse performance than when a diy blend was prepared first and then incorporated into the polymer (Figure 7.1). In this case, pre-blending protected the fiber from breakage. 

Higuera, V., Belzunce, F. J. Ferna ndez Rico, E. (1997). Erosion Wear and Mechanical Properties of Plasma-Sprayed Nickel- and Iron-Based Coatings Subjected to Service Conditions in Boilers. Tribological International, VoL 30, No. 9, p>p. 641-649, ISSN 0301679X... 

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