CROSS REFERENCE TO RELATED APPLICATIONS
[0001] NA
TECHNICAL FIELD
[0002] The present invention relates to methods and apparatus for development of electroless nickel-phosphorous (Ni-P) based coatings and more particularly, methods and apparatus for development of electroless nickel-phosphorous (Ni-P) based coatings for aluminium - silicon alloy pistons and cylinders.
BACKGROUND
[0003] Use of Fossil Fuels like Petrol and Diesel for Automobiles Contribute vastly to C02 emission, contributing to the Green House Effect, causing serious Global Warming , serious weather changes unknown to our planet till recently, that we are all experiencing and paying the price for today, and worsening year after year. This is a great global concern today, and very many Global summits are being held to discuss this matter, to find urgent solutions and to take concrete planned steps.
[0004] One answer to this problem is the use of Bio Fuels (obtained from vegetation / crops and is a renewable source unlike fossil fuels which will exhaust one day or the other). Usage of Bio Fuels reduces the C02 emission by almost 75 - 80 %. Even a Blend of 20 % Bio Fuel to Fossil fuels have shown considerable reduction in C02 emission, bringing with it some hope for our planet and future generations. This is largely the story of the automobile industry. However, one drawback in use of bio-fuels is that they are highly corrosive in nature which results in greater wear and tear and abrasion of engines, and more specifically, pistons and cylinders used in automobiles, two wheelers and other

devices and systems driven by internal combustion engines.
[0005] While electric cars are fast emerging, there are millions of automobiles already on the road,
and a country like India may not be able to enforce the discard of their use immediately.
[0006] There remains a need for internal combustion engines and pistons and cylinders comprised in
such internal combustion engines that can be operated using the aforementioned bio-fuels and/or with
fossil fuels blended with bio fuels For this to happen, the internal combustion engines and pistons
and cylinders comprised in such internal combustion engines, not to mention other moving engine
parts, need to have a much higher corrosion resistance to withstand the wear and tear. At the very
least, pistons and cylinders comprised in such internal combustion engines need a protective coating
that contributes to increased life span of components used in varied conditions. There remains an
additional need for highly heat resistant coatings which further results in an increased LIFE SPAN of
coated components, and greatly reduces servicing and maintenance costs. There remains a need for a
coating that has a high hardness thereby adding to its' durability.
[0007] There remains an additional need for methods and systems wherein coatings can be applied
successfully on both metallic (Aluminium, Steel, brass, Copper as well as Zinc ) and non - metallic
objects (like plastics).
[0008] Yet additionally, there remains a need for a method/process and a system that is energy
conserving with the minimum use of electrical power and is extremely effective especially in
geographies where power supply is erratic and power tripping common.
[0009] There remains a further need for coating systems and methods and coatings thereof, such that
deposits are independent of the geometry of the component being coated so that it can be successfully
used for objects with COMPLEX geometries.
[0010] There is a further need for coatings that provide very good adhesion on all the substrates
mentioned above.
[0011] There remains a need for coatings that offer very good WEAR RESISTANCE
[0012] There remains a need for coatings that provide an effective corrosion barrier.
[0013] There remains a need for coatings having good (natural) lubricity and good anti galling

properties.
[0014] Further, there is a very big scope to use this EL Nickel process with addition of various hard
r
particles (composites), to achieve/improve several desired properties. [0015] Embodiments disclosed address the above shortcomings.
SUMMARY OF THE INVENTION
[0016] According to an embodiment, the present invention relates generally to an electroless nickel
plating bath comprising:
[0017] a) a source of nickel ions;
[0018] b) an effective amount of a reducing agent/reducer, preferably comprising an appropriate
quantity of thiourea;
[0019] c) an effective amount of replenisher to maintain a consistent source of Ni;
[0020] d) a source of hypophosphite ions preferably using Sodium Hypophosphite;
[0021] e) one or more chelating agents; and
[0022] f) optionally, other additives.
[0023] In another embodiment, the present invention also relates generally to a method of providing
a low and medium phosphorus electroless nickel deposit on a substrate, the method comprising the
steps of:
[0024] a) preparing the substrate to accept electroless nickel thereon;
[0025] b) immersing the substrate into an electroless nickel plating bath, the electroless nickel plating
bath comprising:
[0026] i) a source of nickel ions;
[0027] ii) an effective amount of a reducing agent/reducer preferably comprising an appropriate
amount of thiourea;
[0028] iii) an effective amount of replenisher to maintain a consistent source of Ni;
[0029] iv) a source of hypophosphite ions preferably using Sodium Hypophosphite;
[0030] v) one or more chelating agents; and

[0031] vi) optionally, other additives;
[0032] wherein the low and medium phosphorus electroless nickel deposit is capable of passing a
heat quench test, in which the substrate with the low or medium phosphorus nickel deposit thereon is
heated up to a temperature of approximately 250° C - 350° C for a period of one hour before being
immersed in room temperature water.
[0033] According to an embodiment, a chelating agent is a chemical compound in which metallic
and non-metallic, usually and preferably, organic atoms are combined. These compounds are
characterized by a ring structure in which a metal ion is attached to two non-metal ions by covalent
bonds.
BRIEF DESCRIPTION OF DRAWINGS
[0034] The present invention, both as to its organization and manner of operation, together
with further objects and advantages, may best be understood by reference to the following
description, taken in connection with the accompanying drawings. These and other details of
the present invention will be described in connection with the accompanying drawings, which
are furnished only by way of illustration and not in limitation of the invention, and in which
drawings:
[0035] FIG. 1 illustrates an apparatus and method according to an embodiment.
[0036] TABLE 1 illustrates the steps in the method.
[0037] FIG. 2A illustrates cross sections of a component using electrolytic nickel coating.
[0038] FIG. 2B illustrates cross sections of a component using electroless nickel coating.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0039] The following is a detailed description of embodiments of the invention depicted in the accompanying drawings. The embodiments are introduced in such detail as to

clearly communicate the invention. However, the embodiments) presented herein are
merely illustrative and are not intended to limit the anticipated variations of such
embodiments. On the contrary, the intention is to cover all modifications, equivalents,
and alternatives falling within the spirit and scope of the appended claims. The detailed
descriptions below are designed to make such embodiments obvious to those of ordinary
skill in the art.
[0040] Embodiments disclosed include an apparatus for electroless coating of a substrate, and
according to a preferred embodiment a hypereutectic and eutectic Al-Si alloy, the apparatus
comprising: a preparation apparatus for preparing the Al-Si alloy to accept electroless nickel thereon,
the preparation apparatus further comprising, a de-greasing means, a water rinsing means operatively
combined with an air agitation means, an alkaline etching means, a desmutting means, a first zinkate
treating means, a zinkate stripping means, a second zinkate treating means, and an EN striking means.
The apparatus further comprises an electroless nickel coating means in an electroless Nickel plating
bath comprising at least one of an El-Ni-P coating means comprising air agitation, an EL-Ni-P-B
coating means comprising air agitation, and an El-Ni-SiC coating means comprising air agitation.
Preferably the embodiment includes a and a drying and unloading means subsequent to the electroless
nickel coating means.
[0041] As described herein, the present invention relates generally to an electroless nickel plating
bath comprising:
[0042] a) a source of nickel ions;
[0043] b) an effective amount of a reducing agent/reducer preferably comprising thiourea;
[0044] c) an effective amount of replenisher to maintain a consistent source of Ni;
[0045] d) a source of hypophosphite ions preferably using Sodium Hypophosphite;
[0046] e) one or more chelating agents; and
[0047] f) optionally, other additives.
[0048] FIG. 1 illustrates an apparatus and method according to an embodiment. De-greasing step 101
is performed in bath 1. Step 102 performed in bath 2 comprises water rinsing combined with air

agitation. Step 103 comprises an alkaline etching step, performed in bath 3. According to an embodiment, a heater is used in the alkaline etching step. Steps 104 and 105, performed in baths 4 and 5 respectively, are water rinsing steps combined with air agitation. Step 106 is a desmutting step performed in bath 6. This is followed by steps 107 and 108, which are water rinsing steps performed in baths 7 and 8 respectively and combined with air agitation. Step 109, performed in bath 9 and of particular relevance to substrates that comprise eutectic and hypereutectic aluminium alloys, is a first zinkate step. This is followed by step 110 in bath 10, a water rinsing step combined with air agitation. Step 111 is a zinkate strip step performed in bath 11. This is followed by steps 112 and 113, which are water rinsing steps performed in baths 12 and 13 respectively, and combined with air agitation. Step 114 is a second zinkate step, performed in bath 14. This is followed by steps 115 and 116, which are water rinsing steps performed in baths 15 and 16 respectively, and combined with air agitation. Step 117 comprises an electroless nickel strike step, performed in bath 17 utilizing a filter and at least one heater. This is again followed by steps 118 and 119, which are water rinsing steps performed in baths 18 and 19 respectively, and combined with air agitation. Step 120 is the electroless nickel coating step wherein the substrate is immersed in an electorless nickel coating bath comprising at least one of electroless-nickel-phosphorous (El-Ni-P) (bath 20), electroless-nickel-phosphorous-boron (El-Ni-P-B) (bath 21) and electroless-nickel-silicon-carbide (El-Ni-SiC) (bath 22). According to an embodiment, baths 20, 21 and 22 comprise air agitation means and filters to enhance the efficacy of the process, and preferably include 4-6 heaters as well. This is followed by steps 121 and 123, which are water rinsing steps performed in baths 23 and 24 respectively, and combined with air agitation. Finally, the coated substrate is put through a drying and unloading step 123. The coated substrate is now ready for the heat quench test (step 124) prior to dispatch.
[0049] The source of nickel ions can be any suitable source of soluble nickel ions, and is preferably a nickel salt selected from the group consisting of nickel bromide, nickel fluoroborate, nickel sulfonate, nickel sulfamate, nickel alkyl sulfonate, nickel sulfate, nickel chloride, nickel acetate, nickel hypophosphite and combinations of one or more of the foregoing. In one preferred embodiment, the nickel salt is nickel sulfate. The soluble source of nickel ions is present in the plating bath in an amount to preferably provide a concentration of nickel metal in the bath in the range of about 1 to

about 50 g/L, more preferably about 2 to about 20 g/L, and most preferably about 5 to about 10 g/L. According to one embodiment the soluble source of nickel ions is present in the plating bath in an amount to provide a concentration of nickel metal in the bath in the range of 3-7gms/litre. [0050] Nickel ions are reduced to nickel metal in the electroless nickel plating bath by the action of chemical reducing agents which are oxidized in the process. In the case of electroless nickel-phosphorus deposits, the reducing agent typically comprises hypophosphite ions and the hypophosphite ions are preferably selected from hypo phosphorus acid or a bath soluble salt thereof such as sodium hypophosphite, potassium hypophosphite and ammonium hypophosphite. According to an embodiment sodium hypophosphite is used. The amount of reducing agent employed in the electroless nickel plating bath is at least sufficient to stoichiometrically reduce the nickel cation in the electroless nickel reaction to free nickel metal, which concentration is typically in the range of about 0.01 to about 200 g/L, more preferably between about 20 g/L and about 50 g/L. If the concentration of the reducing agent is less than about 0.01 g/L, the plating speed will be reduced and if the concentration of the reducing agent is greater than about 200 g/L, the bath may begin to decompose. In addition, if necessary, the reducing agent may be replenished during the reaction. According to an embodiment, the content of sodium hypophosphite in Ni-P is 20-40 gms/litre, in Ni-P-B is 9-18 gms/litre and Ni-P-SiC is 20-40 gms/litre.
[0051] Examples of carboxylic acids which are useful as the nickel complexing agent the solutions of the present invention include: mono carboxylic acids such as acetic acid, glycolic acid, glycine, alanine, lactic acid; dicarboxylic acids such as succinic acid, aspartic acid, malic acid, malonic acid, tartaric acid; tricarboxylic acids such as citric acid; and tetracarboxylic acids such as ethylene diamine tetra acetic acid (EDTA), which may be used alone or in combination with each other. [0052] According to an embodiment, the present invention relates generally to a method of providing a low and medium phosphorus electroless nickel deposit on a substrate, the method comprising the steps of:
[0053] a) preparing the substrate to accept electroless nickel thereon, the preparation comprising:a degreasing step for degreasing the substrate; an alkaline cleaning step; an acidic etching step; a

zinkate treatment step; and an electroless Nickel strike coating step.
[0054] b) immersing the substrate into an electroless nickel plating bath, the electroless nickel plating
bath comprising:
[0055] i) a source of nickel ions;
[0056] ii) an effective amount of a reducing agent/reducer preferably comprising an appropriate
amount of thiourea;
[0057] iii) an effective amount of replenisher to maintain a consistent source of Ni;
[0058] iv) a source of hypophosphite ions preferably using Sodium Hypophosphite;
[0059] v) one or more chelating agents; and
[0060] vi) optionally, other additives;
[0061] wherein the low or medium phosphorus electroless nickel deposit is capable of passing a heat
quench test, whereby the substrate with the low or medium phosphorus nickel deposit thereon is
heated up to a temperature of 250-350 degrees centigrade for approximately one hour and
subsequently immersed into room temperature water and there is no blistering, cracking and growth
or distortion of the low or medium phosphorous electroless nickel deposit. If the coating/deposit
develops blisters, cracks or/and growth or distortion after heating or/and after immersion in room
temperature water, it fails the heat quench test.
[0062] The substrate may be selected from the group consisting of non-conductive or dielectric
substrates such as plastics and ceramics and metal substrates, including steel, aluminium, brass,
copper and zinc. According to an embodiment, the substrate selected is an AL-Si alloy, and more
particularly, an eutectic or hypereutectic AL-Si alloy.
[0063] The step of preparing the substrate to accept nickel plating thereon typically comprises
cleaning or pre-treating the surface of the substrate prior to metal deposition and the type of cleaning
or pre-treating depends on the substrate material being plated. For example, copper or copper alloy
surfaces may be treated with an etch cleaning method which is typically carried out in oxidizing,
acidic solutions such as a solution of various acids and hydrogen peroxide. Aluminium and
aluminium alloy surfaces may be treated using various zincation treatments. According to a preferred

embodiment, hypereutectic and eutectic Aluminium Silicon alloy surfaces, in addition to various zincation treatments undergo degreasing treatments, alkaline and acidic etching and cleaning treatments, desmutting treatments, and electroless nickel striking treatments prior to coating, and preferably alternated with a water rinsing treatment combined with air agitation. Optionally, coating treatments include an El-Ni-P coating treatment comprising air agitation, an EL-Ni-P-B coating treatment comprising air agitation, and an El-Ni-SiC coating treatment comprising air agitation. [0064] According to an embodiment, nickel sulfate is used as a source of nickel ions. According to one embodiment, a reducing agent like thiourea or its equivalent is allowed to pre-mix with the nickel sulfate prior to their combination with the other bath ingredients, to prevent or inhibit sulphur co-deposition, enabling the El-Ni-P, EL-Ni-P-B, or/and the El-Ni-SiC coated substrate to pass the heat quench test. According to a preferred embodiment, the source of nickel ions, reducer and water are mixed together, and allowed to react before adding the other plating bath components. According to an example embodiment, mixing an amount of 6 to about 150 g/L of nickel sulfate with about 10 to about 50 mg/L of thiourea and then diluting the mixture to the amount described above for the individual concentrations of nickel sulfate prior to combining the nickel sulfate produces an electroless nickel phosphorus deposit having the desired mechanical and physical properties comprising a coating with a strong and cohesive adhesion.
[0065] The use of the electroless nickel phosphorus plating bath described herein produces a faster rate deposition of at least 20 microns/hour, preferably at least 10 microns/hour and most preferably at least 15 microns/hour. This is important because plating rate is a critical process characteristic and in many cases determines the commercial viability of a particular chemistry. According to an embodiment, the properties remain unchanged and consistent until 6-8 metal turnovers (MTO's). [0066] The electroless nickel phosphorus bath described herein is capable of producing a deposit having between 1 and 10% by weight phosphorus in the plating deposit.
[0067] According to an embodiment, the electroless plating deposition rate is further controlled by selecting the proper temperature, pH and metal ion/reducer concentrations. Complexing ions may also be used as catalyst inhibitors to reduce the potential for spontaneous decomposition of the electroless

nickel plating bath.
[0068] According to an embodiment the electroless nickel plating baths can be operated over a broad pH range such as from about 4 to about 10. For an acidic bath, the pH can generally range from about 4 to about 7. According to one embodiment, the pH of the solution is from about 4 to about 6. For an alkaline bath, the pH can range from about 7 to about 10, or from about 8 to about 9. Since the plating solution has a tendency to become more acidic during its operation due to the formation of hydrogen ions, the pH may be periodically or continuously adjusted by adding bath-soluble and bath-compatible alkaline substances such as sodium, potassium or ammonium hydroxides, carbonates and bicarbonates. The stability of the operating pH of the plating solutions of the present invention can be improved by the addition of various buffer compounds such as acetic acid, propionic acid, boric acid, or the like.
[0069] According to an embodiment, the substrate to be plated is immersed in the bath comprising the plating solution at a temperature of about 35° C up to about the boiling point of the solution. Acidic electroless nickel plating baths are typically operated at a temperature in the range of about 60 to about 100° C, more preferably about 70 to about 90° C, while alkaline electroless nickel plating baths are operated within similar but slightly lower temperatures than the acidic electroless nickel plating baths.
[0070] According to an embodiment the substrate is immersed in the electroless nickel plating bath for a sufficient period of time to deposit the desired thickness of the nickel-phosphorus alloy, the nickel-phosphorous boron alloy, or the nickel-silicon-carbide alloy thereon. For example, a contact time can range from as little as about 1 minute to several hours, or even longer. A plating deposit of about 5-15 microns is a desirable thickness for many commercial applications. If wear resistance is desired, thicker deposits can be applied up to about 60 - 100 microns or more.
[0071] According to an embodiment, during deposition of the nickel phosphorus, nickel phosphorous boron, or nickel silicon carbide alloy, mild agitation may be utilized, which may be accomplished by mild air agitation, mechanical agitation, bath circulation by pumping, rotation of a barrel for barrel plating, and other similar means. According to an alternate embodiment, only mild or vigorous air

agitation may be implemented. According to a preferred embodiment, the plating solution may also
be subjected to periodic or continuous filtration treatment to reduce the level of various contaminants
therein. Replenishment of the bath constituents may also be performed, on a periodic or continuous
basis, to maintain the concentration of the bath constituents, including nickel ions and hypophosphite
ions, as well as the pH level, within the desired limits.
[0072] ADVANTAGES OF THE DISCLOSED EMBODIMENTS
[0073] Embodiments disclosed include Phosphorous containing Electroless Ni enabling corrosion
resistance and increased life span of components even under harsh and chemical attack conditions.
Preferred embodiments are highly heat resistant which further results in an increased life span of
coated components, and greatly reduced servicing and maintenance costs. Additionally, the very high
hardness of the phosphorous containing Electroless Ni coating adds to its' durability. The presence of
Phosphorous gives the coating an improvement in hardness, which is noteworthy.
[0074] Embodiments disclosed include Phosphorous containing Electroless Ni coatings, which can
be applied successfully on both metallic (Aluminium, Steel, Brass, Copper as well as Zinc) and non -
metallic objects (like plastics) - a very unique feature indeed.
[0075] Embodiments disclosed include a method that requires minimal use of electrical power, and
is extremely effective especially in geographies where power supply is erratic and power tripping
common. In contrast, the electrolytic electroplating processes get disturbed during power shut
downs thus affecting the coating quality, sometimes even resulting in the rejection of a batch.
[0076] Embodiments disclosed include Electroless Ni coatings, apparatuses and methods for
applying the said Electroless Ni coatings, such that deposits are independent of the geometry of the
component being coated. Hence, it can be successfully used for objects with complex geometries. The
EL Ni coating does not have any corner effect. It coats very uniformly even on sharp edges, deep and
minute holes, threads etc. The internal surfaces, threaded portions also get coated uniformly. In other
words, the coating is very uniform and does not cause excess build up.
[0077] FIG. 2A illustrates cross sections of a component using electrolytic nickel coating.
[0078] FIG. 2B illustrates cross sections of a component using electroless nickel coating.

[0079] Embodiments disclosed include apparatuses and methods for electroless nickel phosphorus
plating baths capable of producing between about 2 and about 8 percent by weight phosphorus in the
plating deposit, depending upon the product and the composite is being plated like Ni-P, Ni-P-B or
Ni-P-SiC.
[0080] Embodiments disclosed provide an electroless nickel phosphorus deposit that has little or no
sulphur in the deposit.
[0081] Embodiments disclosed enable production of electroless nickel deposits capable of passing
the heat quench test.
[0082] Embodiments disclosed enable production of electroless nickel deposits capable of having a
uniform thickness, and of meeting hardness and wear resistance criteria.
[0083] Embodiments disclosed include Electroless Ni Coatings that provide very good adhesion on
all the substrates mentioned above.
[0084] Embodiments disclosed include Electroless Ni coatings that offer very good wear resistance
and good lubricity.
[0085] Embodiments disclosed include Electroless Ni coatings having good ductility.
[0086] Electroless Ni coatings are generally less porous, and thus more robust and stable than
Electro-plated Nickel and Hard Chrome. This property provides an effective corrosion barrier.
[0087] Embodiments disclosed include Electroless Ni coatings having good (natural) lubricity due to
its micro structure (also called CAULI FLOWER STRUCTRE/) which gives the coating good anti
galling properties. This feature makes it very useful for pistons and cylinders.
[0088] It is possible to alter the Electroless Ni coating properties over a wide range by changing the
Phosphorous (P) content.
[0089] Electroless Ni coatings can be applied even in very small thicknesses.
[0090] While the above mentioned features hold good in general for Electroless Ni coatings, and of
interest for application to various components, it is of very specific interest to present context of
Automobile Sector as detailed below.
[0091] Since various possible embodiments might be made of the above invention, and since various

changes might be made in the embodiments above set forth, it is to be understood that all matter herein described or shown in the accompanying drawings is to be interpreted as illustrative and not to be considered in a limiting sense. Thus, it will be understood by those skilled in the art of systems and methods that facilitate manufacture of pistons and piston systems, that although the preferred and alternate embodiments have been shown and described in accordance with the Patent Statutes, the invention is not limited thereto or thereby.
[0092] The figures illustrate the architecture, functionality, and operation of possible implementations of systems and methods according to various embodiments of the present invention. It should also be noted that, in some alternative implementations, the functions noted/illustrated may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. [0093] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
[0094] In general, the routines executed to implement the embodiments of the invention, may be part of an operating system or a specific application, component, program, module, object, or sequence of instructions. [0095] The present invention and some of its advantages have been described in detail for some embodiments. It should be understood that although the system and process is described with reference to electroless nickel coatings of metallic and non-metallic substrates, the system and method is highly reconfigurable, and may be used in other contexts as well. It should also be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the

invention as defined by the appended claims. An embodiment of the invention may achieve multiple objectives, but not every embodiment falling within the scope of the attached claims will achieve every objective. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. A person having ordinary skill in the art will readily appreciate from the disclosure of the present invention that processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed are equivalent to, and fall within the scope of, what is claimed. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps. [0096] While the preferred embodiments of the present invention have been described hereinabove, it should be understood that various changes, adaptations, and modifications may be made therein without departing from the spirit of the invention and the scope of the appended claims. It will be obvious to a person skilled in the art that the present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. [0097] It should also be understood that the following claims are intended to cover all of the generic and specific features of the invention described herein and all statements of the scope of the invention that as a matter of language might fall there between.

CLAIMS

We claim

1.A method of providing alow and medium phosphorus electroless nickel plating
deposit on a hypereutectic and eutectic Al-Si alloy substrate, the method
comprising the steps of:
preparing the substrate to accept electroless nickel thereon; immersing the substrate into an electroless nickel plating bath, the electroless nickel plating bath comprising:
a. a source of nickel ions;
b. an effective amount of a reducing agent;
c. a source of hypophosphite ions;
d. one or more chelating agents; and
e. optionally, other additives;
wherein the low and medium phosphorus electroless nickel deposit is capable of passing the heat quench test in which the substrate with the low and medium phosphorus nickel deposit is heated up to a temperature of 250-350 degrees centigrade for a period of approximately one hour and subsequently immersed in room temperature water.
2. The method of claim 1 wherein preparing the substrate to accept
electroless nickel thereon further comprises:
a degreasing step for degreasing the substrate;
an alkaline cleaning step;
an acidic etching step;
a zincate treatment step; and
an electroless nickel strike coating step.
3. The method of claim 1 wherein preparing the substrate to accept electroless

nickel thereon further comprises: a de-greasing step;
a first water rinsing step comprising simultaneous air agitation; an alkaline etching step;
a second water rinsing step comprising air agitation; a third water rinsing step comprising air agitation; a desmutting step;
a fourth water rinsing step comprising air agitation; a fifth water rinsing step comprising air agitation; a first zinkate step;
a sixth water rinsing step comprising air agitation; a zinkate strip step;
a seventh water rinsing step comprising air agitation; an eighth water rinsing step comprising air agitation; a second zinkate step;
a ninth water rinsing step comprising air agitation; a tenth water rinsing step comprising air agitation; an electroless nickel strike step;
an eleventh water rinsing step comprising air agitation; a twelfth water rinsing step comprising air agitation; and a thirteenth water rinsing step comprising air agitation.
4. The method of claim 1 wherein immersing the substrate into an electroless nickel plating bath further comprises one of:
immersing the substrate into an electroless nickel-phosphorus (El-Ni-

P) plating bath followed by an air agitation, immersing the substrate into an electroless nickel-phosphorus-boron (El-Ni-P-B) plating bath followed by an air agitation, and immersing the substrate into an electroless nickel-silicon-carbide (El-Ni-SiC) plating bath followed by an air agitation;
a fourteenth water rinsing step comprising air agitation;
a fifteenth water rinsing step comprising air agitation; and
a drying and unloading step.
5. The hypereutectic and eutectic Al-Si alloy substrate of claim 1, wherein the hypereutectic and eutectic Al-Si alloy is at least one of a piston and a cylinder.
6. The hypereutectic and eutectic Al-Si alloy substrate of claim 1, wherein the electroless Ni coating on the hypereutectic and eutectic Al-Si alloy has a cauliflower structure.
7. The method of claim 2 wherein:
the degreasing step further comprises removing oil and grease impurities from the surface of the Al-Si alloy.
8. The method of claim 2 wherein the alkaline cleaning and acidic etching steps further comprise activation of the surface of the Al-Si alloy for accepting Nickel ions in the Nickel strike coating step.
9. The method of claim 2 further comprising a desmutting step.

10. The method of claim 2 wherein the zinkate treatment step comprises a first zinkate step, a zinkate stripping step and a second zinkate step.
11. An apparatus for providing a low and medium phosphorus electroless nickel plating deposit on a hypereutectic and eutectic Al-Si alloy substrate, the apparatus comprising:
means for preparing the substrate to accept electroless nickel thereon;
an electroless nickel plating bath for immersion of the substrate, the electroless nickel plating bath comprising:
a. a source of nickel ions;
b. an effective amount of a reducing agent;
c. a source of hypophosphite ions;
d. one or more chelating agents; and
e. optionally, other additives;
wherein the low and medium phosphorus electroless nickel deposit is capable of passing the heat quench test in which the substrate with the low and medium phosphorus nickel deposit is heated up to a temperature of 250-350 degrees centigrade for a period of approximately one hour and subsequently immersed in room temperature water.
12. The apparatus of claim 11 wherein the means for preparing the substrate to accept
electroless nickel thereon further comprises:
a degreasing means for degreasing the substrate; an alkaline cleaning means; an acidic etching means;

a zinkate treatment means;
an electroless Nickel strike coating means.;
at least one of an El-Ni-P coating means comprising air agitation, an EL-Ni-P-B coating means comprising air agitation, and an El-Ni-SiC coating means comprising air agitation; and
a drying and unloading means.
13. The apparatus of claim 11 wherein:
the electroless nickel plating bath further comprises one of an electroless nickel-phosphorus (El-Ni-P) coating means comprising air agitation, an electroless nickel-phosphorus-boron (EL-Ni-P-B) coating means comprising air agitation, and an electroless nickel-silicon-carbide (El-Ni-SiC) coating means comprising air agitation; and
a drying and unloading means.
14. The hypereutectic and eutectic Al-Si alloy substrate of claim 11, wherein the hypereutectic and eutectic Al-Si alloy is at least one of a piston and a cylinder.
15. The hypereutectic and eutectic Al-Si alloy substrate of claim 11, wherein the electroless Ni coating on the hypereutectic and eutectic Al-Si alloy has a cauliflower structure.
16. The hypereutectic and eutectic Al-Si alloy substrate of claim 11, wherein the electroless Ni coating on the hypereutectic and eutectic Al-Si alloy has a hardness of above 550 Hv and increases further when the coated substrate is baked to a temperature of 180°C to 400°C for one to two hours.

17. The apparatus of claim 12 wherein:
the degreasing means further comprises a means for removing oil and grease impurities from the surface of the substrate.
18. The apparatus of claim 12 wherein the alkaline cleaning and acidic etching means further comprises means for activation of the surface of the Al-Si alloy for accepting Nickel ions in the Nickel strike coating step.
19. The apparatus of claim 12 further comprising a desmutting means.
20. The apparatus of claim 12 wherein the zinkate treatment means comprises a first zinkate treatment means, a zinkate stripping means and a second zinkate treatment means.
21. A method for preparing a low and medium phosphorous nickel plating deposit on a substrate, the method comprising: immersing the substrate into an electroless nickel plating bath, wherein the electroless nickel plating bath comprises: premixing nickel ions with a reagent until the nickel ions and the reagent react; diluting the reacted premixture with water; and adding at least one of an effective amount of saccharin, a source of hypophosphite ions, and one or more chelating agents to the reacted premixture.