CS246375B1 - Electrolyte for cathodic deposition of ternary alloys - Google Patents

Abstract

Electrolyte for cathodic deposition of ternary nickel-cobalt-phosphorus alloys, particularly suitable for the production of functional layers of highly stressed machine parts. The electrolyte consists of a mixture of aqueous solutions of nickel(II) amidosulfonate and sulfosalicylate in a concentration of 1.1 to 2.0 M and of a phosphorus compound in a concentration of 0.001 to 0.2 M. Preferably, the electrolyte contains a halide in a concentration of 0.01 to 0.2 M and an ionic and/or non-ionic wetting agent in an amount of 0.1 to 2.0 g/l. The electrolyte may also contain a buffering compound in a concentration of 0.1 to 0.4 M.

Description

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Electrolyte for cathodic deposition of ternary alloys

Electrolyte for cathodic deposition of ternary nickel - cobalt - phosphorous alloys, suitable especially for production of functional layers of highly stressed machine parts. The electrolyte consists of a mixture of aqueous solutions of amidosulfonate and nickel sulfosalicylate at a concentration of 1.1 to 2.0 M and a phosphorus compound at a concentration of 0.001 to 0.2 M. Preferably, the electrolyte contains a halide at a concentration of 0.01 to 0.2 M and an ionic and / or nonionic surfactant in an amount of from 0.1 to 2.0 g / L. The electrolyte may also contain a buffering compound at a concentration of 0.1 to 0.4 M.

246 175

246 37S

The invention relates to an electrolyte for the cathodic deposition of ternary nickel-cobalt-phosphorus alloys, particularly suitable for the production of functional layers of highly stressed machine parts.

Currently, special attention is paid to nickel alloys with phosphorus excreted from aqueous solutions. This is due to the extraordinary properties of these alloys, in particular high hardness and wear resistance. Most of these layers are deposited by an autocatalytic process known as chemical nickel plating. This technology has some significant disadvantages in comparison with galvanic technologies, in particular the high working temperature, which brings a number of technological difficulties and also shows a limited electrolyte life. Therefore, galvanic processes are developed. However, when using nickel-phosphorus alloys at higher temperatures, the originally high hardness and wear resistance are reduced or lost. Therefore, it seems expedient to use cobalt as another alloy, which is known for its excellent properties at higher temperatures. However, technologies for the galvanic deposition of ternary alloys of the nickel-cobalt-phosphorus type have not yet been developed.

These disadvantages are largely eliminated by the electrolyte for cathodic deposition of nickel-based ternary alloys containing at most 45% by weight of cobalt and at most 10% by weight of phosphorus according to the invention. SUMMARY OF THE INVENTION The electrolyte consists of a mixture of aqueous solutions of amidosulfonate and nickel or cobalt sulfosalicylate at a total concentration of electroactive cations (Ni + Co) of from 1.1 to 2M and a ratio of between 30 and 1 and an anion ratio of NH4SOg. (C-γH 2 O 5 S) ^2- 10 to 1 (molar ratio), further comprising phosphorus compounds, ie, hypophosphites, for example nickel and / or phosphorous acid, or salts thereof and / or phosphoric acid, or salts thereof in In another aspect, the invention comprises an electrolyte halide, for example, nickel bromide in a concentration of from 0.01 to 0.2 M. Preferably, the electrolyte may comprise an ionic and / or non-ionic surfactant, e.g. sodium lauryl sulphate in an amount of from 0.1 to 2.0 g / l. According to a last feature, the electrolyte further comprises a buffering compound, for example boric acid, at a concentration of 0.1 to 0.4 M.

The electrolyte according to the invention exhibits, in addition to its considerable economic advantage, a substantially increased stability while maintaining the quality of the galvanically excluded layer of ternary alloys.

Example 1

The electrolyte contained 1 M nickel amide sulfonate, 0.1 M cobalt amide sulfonate, 0.5 M nickel sulfosalicylate, 0.4 M boric acid, 0.02 M phosphorous acid, 0.05 M nickel bromide and 0.5 g / l Neocal .

PH value == 4, electrolysis parameters: temperature 50 ° C, cathodic current density 5 A.dm. The deposited layer contained 16.8% cobalt and 2.6% phosphorus.

Example 2

The electrolyte contained 0.9 M nickel amidosulfonate, 0.45 M nickel sulfosalicylan, 0.15 M cobalt sulfosalicylan,

0.3 M boric acid, 0.1 M nickel phosphate, 0.05 M potassium iodide, 1 g / l sodium lauryl sulphate.

pH - 3.8, temperature 55 ° C, cathodic current density 4 A.dm * ² · The deposited layer contained 28.3% cobalt and 8.2% phosphorus.

Example 3

The electrolyte contained 0.4 M nickel ammonium sulfonate, 0.5 M cobalt sodium amidosulfonate, 0.8 M nickel sulfosalicylate, 0.06 M phosphorous acid, 0.1 M nickel bromide, and 1 g / L of Neokal. pH = 4.5, temperature 43 ° C, cathodic current density 6.5 A.dm ² . The deposited alloy contained 42.6% cobalt and 3.7% phosphorus.

Claims (4)

SCOPE VY N, X L E Z U 246 375 Electrolyte for the cathodic deposition of ternary nickel-based alloys containing not more than 45% by weight of cobalt and not more than 10% by weight of phosphorus, characterized in that it consists of a mixture of aqueous solutions of nickel or cobalt sulphonated sulfonoyl + Co) from 1.1 to 2.0 M and their degree-2 in the range of 30 to 1 and the ratio of NH 2 SO 4: (C 3 H 4 O 2 S) 10 to 1 (molar ratio), further comprising phosphorus compounds, i.e., phosphorous acid, for example nickel and / or phosphorous acid, or salts thereof and / or phosphoric acid, or salts thereof at a concentration of from 0.001 to 0.2 M. 2. Electrolyte according to claim 1, characterized in that it contains a halide, for example nickel bromide, in a concentration of from 0.01 to 0.20 M. 3. Electrolyte according to claim 1, characterized in that it contains an ionic and / or non-ionic surfactant, for example sodium lauryl sulphate in an amount of from 2.0 to 2.0 g / l, 4. An electrolyte according to claim 1, 2 or 3 comprising a buffering compound, for example boric acid, at a concentration of from 0.1 to 0.4 M.