JPS6187896A - Manufacture of nickel plated copper wire - Google Patents

Abstract

PURPOSE:To prevent the cracking and stripping of a film on a copper wire during secondary working such as elongation or twisting by plating the wire with nickel in a sulfamate bath contg. specified amounts of nickel sulfamate, nickel chloride and boric acid. CONSTITUTION:The copper wire is plated with nickel in the sulfamate bath contg. 400-750g/l, especially 700g/l nickel sulfamate, <10g/l, especially <6g/l nickel chloride and 10-40g/l, especially 30g/l boric acid. The pH of the bath is adjusted to 3-5.5, especially 4-5. A brightener, a pitting inhibitor and other additives may be added to the bath.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a manufacturing method capable of manufacturing a nickel-plated copper wire body having excellent workability such as wire drawing.

(Prior art and its problems) Conventionally, nickel plating was applied to the copper wire body for high acclimatization, prevention of discoloration due to chemicals and chemical reactions, improved soldering properties, and improved adhesion to the material to be soldered. is being carried out. For this nickel plating, a so-called Watt bath containing nickel sulfate and nickel chloride as main components is usually used. If the thickness of the plating film obtained by the Watt bath exceeds 5 μm, the nickel plating film will inevitably crack if the nickel-plated steel wire is subjected to processing such as twisting, winding, or wrapping. However, there was an inconvenience that the base copper layer would peel off, making it impossible to maintain the function of the plating. Yes
It is also impossible to process nickel-plated copper wire into thin wire or irregular wire using dies or rolls. Furthermore, in nickel plating using a Watt bath, even if various conditions are changed, it is not possible to increase the cathode current density to 201/dpo or higher, not only in batch plating methods but also in continuous plating methods.
It was difficult to increase plating productivity.

(Object of the invention) This invention was made in view of the above circumstances, and has good workability in secondary processing and wire drawing processing, and furthermore, it has a low content of impurities in the layer. The purpose of the present invention is to provide a method for producing nickel-plated steel wire, which is essential for electric wires, and which has low chemical precipitation, high chemical purity, and good thermal stability and chemical resistance. The method is characterized in that the copper wire is nickel plated in a sulfamic acid bath containing nickel sulfamate as the main component.

(Specific structure of the invention) This invention will be explained in detail below.

The steel wire bodies used in this invention are rolled, wire-drawn copper and steel alloys such as general electrolytic copper, oxygen-free copper, silver-containing copper, cadmium copper, and chromium copper used for electric wires. Either hard copper material or mild steel material can be used, but considering the processing after nickel plating,
In this case, hard copper material is preferable.

The sulfamic acid bath consists of sulfamic acid nickel lN1 (
N ratio 5Ox) *Hiro H, (J, nickel chloride NiCII
A mixed aqueous solution consisting of MbHmo and Ho@HsB Us, with a concentration of nickel sulfamate ranging from 44oo to 7!
.

y//, preferably 700tt/1. The concentration of nickel chloride is less than 10g/, preferably less than 6#/,
The concentration of boric acid is lθ~μOe/1. Preferably 30s/g
, bath pl (preferably φ~j, bath temperature 90
~70°C, preferably ~60°C is used. Note that various additives such as brighteners and pit preventive agents can be added and mixed as necessary.

The copper wire body is subjected to pretreatment such as degreasing treatment and pickling treatment, and then immersed in a plating bath having the above composition to be plated. The copper wire body is connected to the cathode by a power supply, a liquid power supply, or the like.

For the anode, electrolytic nickel, devolized nickel, a decomposed nickel plate containing a small amount of sulfur, etc. are used, but a decomposed nickel plate containing 0.0/-002% sulfur has particularly high solubility. preferable. The cathode current density is 10 to 10 dc
01/d-delal. During electroplating, the plating bath is vigorously stirred and continuously filtered. The thickness of the nickel plating film is atμ to 200μ, but if wire drawing processing after plating is taken into account, it should be less than 100μ, preferably less than fOμ, and the thickness of the nickel plating film should be between atμ and the diameter of the base copper wire. The ratio of /Q-1 to 10-'', preferably /
X10su~lθX/0-'.

(Function) Under these conditions, the nickel plating film on the nickel-plated round steel wire has good adhesion, the internal stress generated in the film is zero or only a slight compressive stress, and the malleability quickly changes. ing. Therefore, in the copper wire body nickel-plated under the above conditions, the nickel plating film will not crack or peel off even during processing such as twisting and winding. On the other hand, the disadvantage of conventional Watt baths is that internal stress becomes tensile stress even if it can be adjusted slightly by adjusting plating conditions and additives.

The drawing shows an example of the nickel-plated @copper wire body formed as described above, and the symbol ■ in the figure is the @ wire body, and 2 is the nickel plating film.

In addition, the copper wire body plated with nickel under the above conditions can be processed into small-diameter thin wires or irregularly shaped wires using a die scroll, etc., if necessary. It is desirable to keep the area reduction rate as low as 30%, and to use a hard metal processing oil containing extreme pressure additives, etc. as the processing oil.

If the fL′fc nickel wire @copper wire produced by the method of the present invention is wire-drawn under such processing conditions, the nickel wire will tear itself and split f'L. It follows the plastic deformation of the base steel material well, and produces fine nickel-plated wire with excellent f.It is possible to supply the plated wire to the next workpiece, such as I'1, by drawing it down and simultaneously connecting and cutting it. This is different from sending out plated wire from a fine wire plating 7E bobbin in a separate process.) There are no crests, bites, winding curls, or scratches that are typical of A wire.

(Example) Hereinafter, the present invention will be specifically explained with reference to Examples.

[Example 1] Hard copper with a diameter of /m was continuously nickel plated under the plating conditions shown in Table 1.1. - A nickel plating film with a thickness of ψμ was formed. The obtained rL nickel-plated single wire was twisted into seven twists to create a stranded wire, and the surface condition of the nickel plating film of this stranded wire was observed. Still, a nickel-plated single wire was wound around its own diameter, and the surface condition of the nickel-plated film was similarly observed. The results are shown in Table 2.

Table 1 (Note) A sulfur-containing electrolytic nickel plate 5N-AP (manufactured by Shimura Kako) was used as the anode.

Table ■The internal stress during plating was measured using a Spigil contract meter (Yamamoto Plating Test Instruments Co., Ltd.), with a positive value indicating compressive stress and a negative value indicating tensile stress.

[Example 2] Standard Watts bath and sulfamic acid bath (nickel sulfamate 700y/L, nickel chloride ttt/1, HoeR
30e/1. HL flow density 117A/dm, bath temperature 60℃, p
HμJ and tOμ4 for an electrical steel hard copper wire with a diameter of 2IIIφ.
Nickel plating of
Nickel plating with a thickness of Qμ is formed by a continuous plating method, and the nickel-plated single wire with a thickness of 7n is then drawn using a continuous wire drawing machine using mineral oil-based lubricants (■ Ultracut, Sumiko (manufactured by Lubrication Co., Ltd.),
The wire drawing process is performed by dividing the area reduction rate of one drawing by 1%, and the diameter Q
I made a thin line with the same name. The surface condition of the obtained thin wire was observed. Mano, the thin wire was wound with its own diameter, and its surface condition was observed by the blackening of the copper caused by sodium polysulfide. The changes in copper wire diameter and Q ratio were investigated. Summarize the obtained results @3
Shown in the table.

(Effects of the Invention) As explained above, since the method for producing a nickel-plated copper wire of the present invention involves nickel plating in a sulfamic acid bath, the dense M annotation of n9 nickel plating skin + fi is formed. It has low internal stress, excellent ductility, and is composed of high-purity nickel precipitates. Therefore, even after secondary processing such as elongation and wire stranding, the nickel plating film has no ′, ll1r′L, or peeling. etc. will not occur. ts'h, the #1 wire obtained by wire drawing the nickel-plated steel filament obtained by the manufacturing method of the present invention is a continuous wire such as fine wire plating and rolling. It is of very good quality, with no piles, bites, curls, or scratches that are typical of lines that are then supplied to the next factory. Furthermore, since nickel plating can be performed at high current density, productivity is also improved. In addition, the purity of the nickel precipitate is high, so the resulting nickel-plated striped body has a particularly high thermal stability, chemical resistance, and corrosion resistance. .

[Brief explanation of drawings]

The drawing is a cross-sectional view of a nickel-plated copper wire obtained by the manufacturing method of the present invention. ■・・・・・・Copper wire body, 2・old・nickel plating film exposed condyle Bokuraden @ Kano Co., Ltd.

Claims (1)

[Claims] Nickel plating characterized by applying nickel plating to a copper wire body using a sulfamic acid bath consisting of 400 to 750 g/l of nickel sulfamate, 10 g/l or less of nickel chloride, and 10 to 40 g/l of boric acid. A method for manufacturing a copper filament.