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Nickel coatings, electroless

In contrast to electrolytic nickel coating, electroless nickel coating, is deposited without any current as the name indicates. The metal is formed by the reduction of nickel ions in solution by a reducing agent. Sodium hypophosphite is used as a reducing agent. The following is the mechanism of reduction. [Pg.414]

K. Parker, Internal Stress Measurements of Electroless Nickel Coatings by the Rigid Strip Method, ASTM STP 947, American Society for Testing and Materials, Philadelphia, Pa., 1987. [Pg.167]

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. [Pg.535]

Resistance to abrasion The resistance to abrasion of electroless nickel-phosphorus hardened to 600 Hy, assessed by Taber abrasion tests, has been found to be double that of electroplated nickel However, electroless nickel coatings are not suitable for applications where two electroless nickel surfaces rub together without lubrication unless the values of hardness are made to differ by over 200 Hy units. Galling of aluminium, titanium or stainless steel may be overcome by applying electroless nickel to one of the two mating surfaces. [Pg.538]

Electroless nickel coatings containing PTFE particles have been discussed by Tulsi, and non-stick coatings of electrodeposited nickel containing 30% by volume PTFE particles are described by Naito and Otaka . They found that the addition of organic additives to increase the hardness of the nickel matrix to 500-600 Hy reduced the incorporation of the PTFE to 10-15% by volume. [Pg.541]

Some firearms are plated with anodized aluminum, nickel, or chromium which gives durability and good looks, and some are made from stainless steel which is much less prone to rust than conventional steel. Electroless nickel coating is an alloy coating of 88% to 96% nickel and 4% to 12% phosphorus, which is produced by chemical (not electrical) reduction of nickel on to the metal surface. [Pg.100]

Corrosion properties of electroless nickel coatings with codeposited PTFE or silicon carbide (SiC) particles in H2SO4 and NaCl... [Pg.281]

S. Haag, M. Burgard and B. Ernst, Pure Nickel Coating on a Mesoporous Alumina Membrane Preparation by Electroless Plating and Characterization, Surf. Coat. Technol., 201, 2166-73 (2006). [Pg.152]

Electrochemical deposition (electroplating) has traditionally been, and is still, the dominating technique for application of nickel coatings. In recent years, the number of applications of chemical (electroless) deposits of nickel has been growing (parts in pumps, valves, compressors, storage vessels for chemicals etc). [Pg.284]

Nickel-coated poly-p-phenylene terephthalamide film was prepared as follows. A section of poly-p-phenylene terephthalamide film was immersed momentarily in a 0.1 M solution of K+ 0-t-Bu in DHSO and then in a 0.1 M solution of silver trifluoroacetate in DHSO. The film was washed liberally with water and dried. Nickel was plated onto this silver-activated film using a known method of electroless plating as follows a section of film weighing 0.038 g was immersed in a solution of 5.0 g of nickel chloride hydrate and 0.2 g of dimethyl amine borane in a mixture of 50 mL of water and 50 mL of dimethyl formamide for 1.5 hrs. The film was then rinsed liberally with water and dried in a vacuum oven at 110 C for 2 hrs. The resulting nickel coated film weighed 0.095 g and was electrically conductive. [Pg.53]

Coatings are also produced by electroless plating—that is, by chemical reduction of metal-salt solutions, with the precipitated metal forming an adherent overlay on the base metal. Nickel coatings of this kind are called electroless nickel plate. [Pg.270]

The electroless deposition technique has a special application in the chromium plating of plastics, particularly for automobiles. A primary nickel coating is nsed to obtain the conducting layer necessary for the subsequent electrodeposition of chrominm or other metals. A common practice is to coat the electroless Ni first with Cu, then with more Ni and finally with very thin Cr, all by electroplating techniques. [Pg.1073]

Metals which apparently cannot be nickel-coated from hypophosphite solntions are Zn, Cd, Pb, Sb, Bi, Sn, Mo and W. Small amounts of these metals in the electroless plating solntion can stop the deposition of nickel on to other metal surfaces. [Pg.1073]

S. A. Watson, Electroless Nickel Coatings, Technical paper 10055, Nickel Development Institute, Toronto (1990). [Pg.1012]

Nickel coatings can be applied by electrodeposition or electrolessly from an aqueous solution without the use of an externally applied current. [Pg.371]

Duncan, R. N. and Amey, T. L., Performance of Electroless Nickel Coatings in Food Products, Paper 101, CORROSION 84, NACE, 1984. [Pg.825]


See other pages where Nickel coatings, electroless is mentioned: [Pg.132]    [Pg.134]    [Pg.108]    [Pg.109]    [Pg.113]    [Pg.158]    [Pg.108]    [Pg.109]    [Pg.113]    [Pg.158]    [Pg.370]    [Pg.276]    [Pg.108]    [Pg.109]    [Pg.113]    [Pg.158]    [Pg.293]    [Pg.474]    [Pg.66]    [Pg.67]    [Pg.71]    [Pg.855]    [Pg.867]    [Pg.166]    [Pg.529]   
See also in sourсe #XX -- [ Pg.13 , Pg.89 , Pg.95 ]

See also in sourсe #XX -- [ Pg.13 , Pg.89 , Pg.95 ]




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