The term "electroless process" is used to describe methods of plating by means of chemical reduction. Electroless nickel is produced by reducing nickel ions from solutions which contain phosphite, boron or hydrazine compounds. Electroless nickel deposits are not pure nickel but contain substantial amounts of phosphorus. The phosphorus content can be varied, normally between 2-13%, to control strength, ductility, stress, magnetic properties and structure. The phosphorus content of deposits is strongly affected by the bath pH; phosphorus content increases with decrease in pH. Acid baths in common use produce deposits containing about 7- 13% phosphorus. An increase in hypophosphite concentration increases the phosphorus content of deposits from a bath of given pH. The phosphorus content of deposit is affected by bath temperature.
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