JPS60165393A - Composite electroplating bath - Google Patents

Abstract

PURPOSE:To provide a composite electroplating bath capable of imparting abrasion resistance or other properties to a plated iron-phosphorus film on a sliding member, wherein water-insoluble particulates or fibers are incorporated in an electroplating bath containing ferrous ions and a water-soluble phosphorus compound. CONSTITUTION:A composite electroplating bath is obtained by dispersing at least one water-insoluble substance selected from metals, water-insoluble inorganic or organic particulates and fibers into an iron-phosphorus electroplating bath. The plated film obtained by using said bath comprises a plated iron-phosphorus film as a parent phase and said particulates or fibers dispersed as eutectoid in the parent phase. Accordingly, since the parent phase is the plated iron-phosphorus film, the composite plated film have favorable mechanical properties, to which the properties of the eutectoid particulates or fibers are effectively added.

Description

[Detailed description of the invention] The present invention uses an iron/phosphorous plating film as a matrix, and metal,
The present invention relates to a composite electroplating bath capable of obtaining a composite plating film in which one or more water-insoluble substances selected from inorganic and organic fine particles and fibers are dispersed.

Conventionally, sliding members such as the piston skirt that slides against the cylinder bore have a high wear resistance.

In order to improve seizure resistance, various surface treatments have been carried out. As one of the surface treatment methods for such sliding members, it is conventionally known to form an iron/phosphorus plating film on the surface of the sliding member using a Tekken phosphorus electroplating bath. The formation of a plating film improves the wear resistance of sliding parts.

Seizure resistance can be improved, but in order to further extend the life of sliding members, it is desirable to further improve the wear resistance of the iron/phosphorus plating coating, and to add other properties. It is rare.

In view of the above circumstances, the present inventors investigated ways to further improve the mechanical properties of the iron/phosphorus plating film and to add other properties. It has been found that the above object can be achieved by dispersing one or more water-insoluble substances selected from insoluble inorganic and organic fine particles and fibers and performing composite plating.

In addition, in this case 5, as the Tetsujirin electroplating bath which is the basis of the composite electroplating bath of the present invention, a plating bath containing divalent iron ions, hypophosphorous acid and/or hypophosphite and aluminum ions, Or divalent iron ions and phosphorous acid and/or
It has also been found that when a tightening bath containing phosphite as a main component is used, a tightening film with no crank and excellent mechanical properties can be obtained. That is, conventionally known iron/phosphorus electroplating baths contain divalent iron ions and hypophosphorous acid or its salt, and further contain boric acid, ammonium chloride, etc.; According to their side, when iron/phosphorous electroplating is performed using this type of plating bath,
A large number of cranks occur on the cross section of the resulting iron/stainless steel/plated coating, and these cranks are a major obstacle in applications that require particularly mechanical performance.
The phosphor plating film itself has extremely low toughness.

It has been discovered that the Kuzabi effect completely reduces the toughness of the plated material itself. However, a plating bath containing divalent iron ions, hypophosphorous acid and/or hypophosphite, and aluminum ions, or divalent iron ions and phosphorus as described above as an iron/substance electroplating bath, It has been found that when sliding members, etc. are plated using a tightening bath containing acid and/or phosphite as a main component, a plated film without cranks can be obtained.

Furthermore, as a Tekken phosphorus plating film, the phosphorus content is over 10 p.
Less plating film, preferably phosphorus content 0.1-6
It was discovered that the seizure resistance could be further improved when a plating film of 1.5% was obtained, and this led to the present invention.

The present invention will be explained in more detail below.

The composite electroplating bath according to the present invention is an iron/phosphorus electroplating bath in which one or more water-insoluble substances selected from gold, water-insoluble inorganic and organic fine particles, and fibers are dispersed.

In this case, the water-insoluble substance selected from gold, water-insoluble inorganic and organic fine particles, and fibers is appropriately selected depending on the properties required for the plating film, and examples include various metal powders, M2O3+ 5t02 + Zr0z + Tie
□, oxides such as Th02 * y2o31 ceo3, 5i3N4°TiN, BN, C-BN,
etc., TtC, WC, SIC*cr3c2.
Carbide such as B4C, ZrC, ZrB2 + Cr3B
borides such as fluoride graphite, diamond, etc., 'MoS2. Other inorganic fine particles, fluororesins such as polytetrafluoroethylene, epoxy #4
fat, comb latex, other organic fine particles, glass fibers, carbon fibers, various residual whiskers, and other inorganic fibers 1 Various organic fibers are available, and one or more of these may be used, but in particular When plating a sliding member, a hard or lubricating material is preferably used.

In addition, the average particle size of the fine particles is 01/200μ.
In particular, it is preferable to use fibers with a diameter of 0.1 to .20μ, and the length of the fibers is 0.01 to 2000μ.

In particular, it is preferable to use 0.1 to 60 μm.

Further, the amount of these fine particles and fibers added is 5 to 5 oooy, especially 20 to 100 F, per liter of plating solution. : It is preferable to do so.

The iron/phosphorus electroplating bath in which at least one water-insoluble substance selected from gold R% inorganic and organic fine particles and fibers is dispersed contains divalent iron ions and a water-soluble phosphorus compound.

Here, the source of divalent iron ions is not particularly limited, but examples include ferrous sulfate and ferrous chloride.

Examples include ferrous sulfamate and ferrous boronate, and one type of these can be used alone or two or more types can be used in combination. Also.

Although the content of divalent iron ions is not necessarily limited, it is preferably 20 to 80 F per plating bath 11.

In addition, as water-soluble phosphorus compounds, hypophosphites such as primary hypophosphorous acid and sodium hypophosphite, phosphites such as tinous acid and sodium phosphite can be suitably used, and these One type can be used alone or two or more types can be used in combination. The amount of these phosphorus compounds used is also not limited, but it is preferably 90.05 to 20 y per 11 plating baths.

In this case, hypophosphorous acid or hypophosphite can be used alone as the phosphorus compound.

In particular, a bath using primary hypophosphorous acid and/or hypophosphite and an aluminum compound added thereto, or a bath using phosphorous acid and/or phosphite is preferable. When electroplating is performed using a plating bath of the following types,
An iron/phosphorus plating film with no cranks in the cross section can be obtained, and the wear resistance can be further improved. That is, conventionally, when obtaining an iron/phosphorus plating film by electroplating K as described above, a plating bath using hypophosphorous acid or hypophosphite as a phosphorus source has been used.

This type of plating bath produces a shiny plating film, but when the cross section was observed, many cranks were observed. However, should aluminum ions be added to a soaking bath using hypophosphorous acid or hypophosphite as a phosphorus source?

Alternatively, when phosphorous acid or phosphite is used in place of hypophosphorous acid or hypophosphite, it is possible to prevent the formation of cranks on the iron e IJ plating film.

Note that examples of the aluminum compound include aluminum sulfate and aluminum chloride.

It is not limited to this. One of these aluminum compounds may be used alone.

Two or more types may be used in combination. In addition, the aluminum ion content is 7 nights 11! 0.05 per hit
It is preferable to set it to 5f%, especially 0.1 to 2v, and within this range, the effect of preventing rack occurrence is not good.

'Furthermore, the plating bath of the present invention contains a water bathable titanium compound and/or
Alternatively, a turconium compound can be added, thereby making it possible to obtain a composite plating film with even better wear resistance. Here, as the titanium compound and the turconium compound, for example, Na2 TtFa +&TiFa +
(N)L)pTiF, , Ti (804)2 r I'
h, ZrF6, 2ZrFa r(1”@) x Zr
F.

Examples include Zr (so+)t.4H20, and one or more of these can be added. The amount of addition is 0.05-.10y of titanium or zirconium per plating solution, especially 0.1-5.
It is preferable to set it as F.

In addition to the above-mentioned components, the plating bath according to the present invention may further contain 0 to 200% of ammonium sulfate, ammonium chloride, etc. as conductivity salts, if necessary.

In particular, 20-150 l/l, pH buffering agent
C-bowl from 0 to 60y/l, especially 20”-5Uy/
13, Acidic ammonium fluoride, etc. as a complexing agent for divalent or trivalent iron ions fO~20! jl/1. Special K 1~
101/1 can be added. 1. Additionally, a surfactant may be added to uniformly disperse the fine particles or fibers.

Note that the pH of the plating bath of the present invention is preferably 0.5 to .3.5.

When plating the object to be plated of 19 (J) using the composite plating bath described above, the bath temperature is room temperature to 80℃, and the temperature is 30 to 7%.
0°C, and the current density of the cathode layer 1 is (J, 5
~3 Q A/dm", especially 2~2 (J A/d-
It can be done. Further, although stirring is not necessarily required, bath stirring using a cathode roncar, stirrer, or pump can also be employed. Note that an iron plate is generally used for the anode.

The plating film produced using the composite plating bath of the present invention has an iron/phosphorous plating film as a matrix, and fine particles or fibers dispersed in the plating bath are eutectoid and dispersed in this matrix. Since the matrix is an iron/phosphorus plating film, it has good mechanical properties, and the properties of eutectoid fine particles or fibers are effectively imparted5. , as mentioned above, a plating bath containing hypophosphorous acid and/or iX, hypophosphite, aluminum ions, and gold, or divalent iron ions, phosphorous acid, and/or phosphite, and all main components. When plating is carried out using an accumulating bath, a plating film is obtained that has no crank and has even better properties, and the addition of water-soluble titanium compounds and zirconium compounds further improves the wear resistance of the plating film. The same as above can be achieved, and still further, the phosphorus content of the plating film can be lower than that of the present invention.

By setting the phosphorus content to more preferably 0.1 to 6%, the seizure resistance of the plating film can be further improved. Therefore, the composite electroplating bath of the present invention is suitably used for plating sliding members such as piston skirts.

Hereinafter, reference examples and examples will be shown, but the present invention is not limited to the following examples.

FeSO4・7 I20 250 P/ 1tNH4C
150# H3B0320 NH4F fist HF 5 # All 2 (SO4) 3・ni 4-18H201#Na
H2PO2@H200,1N pH1,8 [Reference Example 2J FeC/2@4H20160P// (NH4)2So4100 y H3BO3' 20 # Nu4F#HF 5 # AA! 2 (SO4) Iso・14-181820 5
#NaH2PO2・H2O5I PH1,4 Reference Example 3] F13(N)I2SO3)2 50 P/I as Fe
NI (4C15# NH4F・HF 5' All 2 (804) a・14-181-120
2 1NaH2PO2@H2010z PH2,4 Reference Example 4] FeSO4-'7n2o 250! ! /13(N)I
4) 2S04100# NaH2PO3e 2H201y , H2,1 [Reference Example 5J FeSO47I (20250P/13 NI-14C/ 50'H3BO320# NaH2PO3@2H2021 PH1,8 Reference Example 6"FeCl2"4H,202 20P/1 NH41i'-)IF 10 #A#z(SO4)a・14-18H205#H3PO3
1,5N pH 1,2 Next, using the above plating bath, bath temperature 60°C 1Dk4A
/ Article 2: 30μ iron/phosphorous electroplating was applied to AC8A-T6 standard aluminum alloy.

For comparison, the following plating bath was used, and the bath temperature was 55°.
C1Dk10A/Ad1t? 30μ iron/phosphorus electroplating was applied to an AC8A-T6 standard aluminum alloy under the following conditions.

[Reference example 7] FeC12I+411□080y-/1FeSO4@7
H20100# (N [(4)2SO425# NaH2PO2* I20 1 g #pH 1,4) The obtained iron/phosphorus plating film was cut, and the cut surface was etched with 5% nital for 2 seconds, and then the metal The presence or absence of cranks was examined using a microscope (400x magnification).As a result, no cranks were observed in Reference Examples 1-6, but many cranks were observed in Example 7. Next, examples will be shown.

[Example 1] FeSO4・7H20250fP/13(NI(4)2
So4100 # Na1(2PO3* 2 I20 1 tC-BN 3
0 N pH2, 1 [Example 2] FeCl2"4H20160f/l (1'JH4) 2so4100 w H3B0320I Chaos I4F#HF 5' A62 (S04) 3-14-18H205#Na112
PO2sH203y Na22rF62 # Polytetrafluoroethylene 25! /1pl(1,
4 Using the plating bath shown in Examples, the bath temperature was 60°C.

Dk 4 A/drr? When plating was performed on a steel plate under Starcy stirring, an iron/phosphorus composite plating solution with good lA appearance and uniform eutectoid dispersion of water-insoluble fine particles (C-BN, polytetrafluoroethylene) was found. Obtained. Furthermore, the wear resistance of these composite plating films was good.

Applicant: Uemura Kogyo Co., Ltd. Toyota Motor Corporation Representative Patent Attorney Takashi Kojima

Claims (1)

[Claims] 1.Divalent iron ion and water-soluble phosphorus compound. A composite electroplating bath characterized by containing one or more water-insoluble substances selected from metals, water-insoluble inorganic and organic fine particles, and fibers. 2. The composite electroplating bath according to claim 1, wherein the water-soluble phosphorus compound is hypophosphorous acid and/or hypophosphite, and an aluminum compound is added. 3. The composite electroplating bath according to claim 1, wherein the water-soluble phosphorus compound is phosphorous acid and/or phosphite.