CN1766173A - The preparation method of low-stress, antiwear and antifriction gradient Ni-Co nanometer alloy plate - Google Patents

Abstract

The invention discloses the preparation method of a kind of low-stress, antiwear and antifriction gradient Ni-Co nanometer alloy plate.Mainly big, the problems such as bonding strength is low, antiwear and friction reduction property difference of the thick-layer nano-alloy plating layer internal stress at present preparation are invented.The present invention adopts electro-deposition method, in the basic electrolyte of sulfur acid nickel and cobalt chloride, prepare compact structure by the concentration and the corresponding electrodeposition time of control that increase cobalt salt in the electrolytic solution gradually, surfacing, combine firmly with ground, cobalt contents is the gradient Ni-Co nanometer alloy plate of obvious graded.The internal stress that composition that the graded alloy coating that its advantage is to prepare is had and structure gradient have reduced thickness coating effectively shows excellent wear-resistant and antifriction performance.Therefore be applicable to the parts that require high abrasion and good antifriction quality simultaneously, be expected to be applied to the Precise Alloy electroforming simultaneously and produce.

Description

The preparation method of low-stress, antiwear and antifriction gradient Ni-Co nanometer alloy plate

Technical field

The present invention relates to the preparation method of a kind of low-stress, antiwear and antifriction gradient Ni-Co nanometer alloy plate.

Background technology

Nanocrystalline material is compared the physical and chemical performance with a series of uniquenesses with conventional crystalline material, has been subjected to the extensive concern of scientific circles and industry member as a class advanced material.Nanoalloy is as a class important kind of nano material, and the ideal that progressively becomes many industrial application is selected.The preparation method of Nanoalloy has multiple, and wherein electrodip process has that equipment is simple, energy consumption is low, depositing temperature is low, easy to operate and low cost and other advantages.Relation between Nanoalloy grain-size and stress be studies show that, nano-alloy plating layer can produce very high internal stress in the electrocrystallization process, can cause peeling off and ftractureing of coating, thereby to the solidity to corrosion of nano-alloy plating layer, fatigue strength, wear resistance and magnetic all can produce bigger influence.Especially in electroforming industry, the thick-layer nano-alloy plating layer of preparation low-stress even zero stress has important use value and application prospect, and therefore higher internal stress is the obstacle that electrodip process prepares the Nanoalloy material in the thick settled layer.At present,, require coating to have resistance to abrasion and friction reducing effect preferably simultaneously, to reduce that secondary abrasion loss is joined in friction along with the continuous development of workpiece surface wear resistant coating.If there is higher internal stress in the various coating that use as the wear resistance surface, will significantly reduce the work-ing life of coating.Therefore prepare low-stress, the nano material of antiwear and antifriction becomes the focus and the difficult point of people's research gradually.The Ni-Co alloy is owing to have a good solidity to corrosion, aesthetic color and good wear resistance and excellent magnetism etc., and be widely used as ornamental, function protective coating and magneticsubstance.In addition owing to its preferably mechanical property be widely used as the electroforming moulding stock.But, at present both at home and abroad about less at the correlative study big, problems such as bonding strength is low, antiwear and friction reduction property difference of thick-layer nanometer nickel-cobalt alloy layer internal stress.

Summary of the invention

The object of the present invention is to provide a kind of preparation method of thicker gradient nickel cobalt nano-alloy plating layer,, make gradient layer have corresponding structure and capability gradient by forming the graded of content in the control alloy.Thereby it is big to solve the nano-alloy plating layer internal stress, the problem of function singleness.Prepare with ground bonding strength height, have rice alloy layer in the gradient Ni-Co of excellent antiwear and friction reduction property.

The objective of the invention is to realize by following measure:

The preparation method of rice alloy layer in a kind of low-stress, antiwear and antifriction gradient Ni-Co is characterized in that adopting the electrodip process preparation, and electrolytic solution is by single nickel salt, sodium-chlor, and boric acid, cobalt chloride and sodium saccharinate are formed; The pure nickel sheet is an anode during galvanic deposit, will make negative electrode through pretreated iron and steel, copper metal works before the conventional plating, controls plating temperature at 40～45 ℃, electrolyte ph 3～4.5, current density 3～5A/dm ²Concentration and control corresponding sedimentary time by increasing cobalt chloride in the electrolytic solution gradually in the deposition process:

Cobalt chloride concentration in the electrolytic solution (g/L) electrodeposition time (min)

0 30

2 30

10 30

20 30

40 30

80 90

Can disposablely deposit the gradient Ni-Co nanometer alloy plate that thickness surpasses 150 μ m.

Contain 190-210 gram single nickel salt in every liter of electrolytic solution of the present invention, 19-21 restrains sodium-chlor, and 28-32 restrains boric acid, 0～80 gram cobalt chloride and 1～4 gram sodium saccharinate.

Rice alloy layer compact and uniform structure in the gradient Ni-Co that the present invention prepares, surfacing, the surface has reached the effect of minute surface light.The alloy layer average grain size is at 16-24nm, and graded alloy coating is along thickness direction, and Co content slowly is increased to 81wt.% from 0wt.%.Gradient Ni-Co alloy layer phase structure progressively carries out the transition to close-packed hexagonal structure (HCP) by face-centred cubic structure (FCC).The internal stress of gradient nano alloy layer reduces by 10～14 times than the rich cobalt-base alloy coating of homogeneous individual layer.The dry friction and wear test shows that the resistance to abrasion of gradient nano alloy layer reduces 4-6 doubly than nanometer Ni and low cobalt alloy coating, and frictional coefficient reduces about 2 times (remaining on 0.20～0.26).The present invention is at iron and steel, and rice alloy layer process stabilizing is simple to operate in the thick gradient Ni-Co of workpiece surface plating such as copper, invests little.The existing higher resistance to abrasion of the gradient Ni-Co nanometer alloy plate of preparing has good antifriction performance simultaneously.Therefore be applicable to the parts that require high abrasion and good antifriction quality simultaneously, as require wear-resisting with lubricated component such as motor car engine.Its lower internal stress is expected to make it further to be applied to Precise Alloy electroforming production simultaneously.

Description of drawings

Fig. 1 is that the component gradient of gradient nickel cobalt nano-alloy plating layer section of the present invention distributes.

Fig. 2 is a gradient nickel cobalt nano-alloy plating layer frictional coefficient curve of the present invention.

Embodiment

Embodiment 1:

Make anode with the pure nickel sheet, pending workpiece is made negative electrode.The solution composition of galvanic deposit gradient Ni-Co nanometer alloy plate is as follows: contain 200 gram single nickel salts in every liter of electrolytic solution, 20 gram sodium-chlor, 30 gram boric acid, 0～80 gram cobalt chloride and 1～4 gram sodium saccharinate.Plating temperature is maintained 40～45 ℃, plating bath pH value 3～4.5, current density 3～5A/dm ²Will be through the conventional chemical oil removing, iron and steel after acidic activated, the copper metal works, by carrying out galvanic deposit under above-mentioned solution composition and the processing condition, increase cobalt salt concentration and control corresponding sedimentary time (seeing Table 1) gradually according to the technology shown in the table 1 in the deposition process, can be on workpiece once property deposit the gradient Ni-Co nanometer alloy plate of thickness greater than 150 μ m.

Table 1 gradient Ni-Co nanometer alloy plate galvanic deposit control condition

Cobalt chloride concentration in the electrolyte (g/L) 02 10 20 40 80

Electrodeposition time (min) 30 30 30 30 30 90

Claims (2)

1, the preparation method of a kind of low-stress, antiwear and antifriction gradient Ni-Co nanometer alloy plate is characterized in that adopting electrodip process preparation, and electrolytic solution is by single nickel salt, sodium-chlor, and boric acid, cobalt chloride and sodium saccharinate are formed; The pure nickel sheet is an anode during galvanic deposit, will make negative electrode through pretreated iron and steel, copper metal works before the conventional plating, controls plating temperature at 40～45 ℃, plating bath pH value 3～4.5, current density 3～5A/dm ²Concentration and control corresponding sedimentary time by increasing cobalt chloride in the electrolytic solution gradually in the deposition process:

Cobalt chloride concentration in the electrolytic solution (g/L) electrodeposition time (min)

0 30

2 30

10 30

20 30

40 30

80 90

Can disposablely deposit the gradient Ni-Co nanometer alloy plate that thickness surpasses 150 μ m.

2, as the said method of claim 1, it is characterized in that containing in every liter of electrolytic solution 190-210 gram single nickel salt, 19-21 restrains sodium-chlor, and 28-32 restrains boric acid, 0～80 gram cobalt chloride and 1～4 gram sodium saccharinate.

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