CA1303802C - Gold colored ware - Google Patents
Gold colored wareInfo
- Publication number
- CA1303802C CA1303802C CA000533536A CA533536A CA1303802C CA 1303802 C CA1303802 C CA 1303802C CA 000533536 A CA000533536 A CA 000533536A CA 533536 A CA533536 A CA 533536A CA 1303802 C CA1303802 C CA 1303802C
- Authority
- CA
- Canada
- Prior art keywords
- nickel
- gold
- base
- layer
- decorative
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- A—HUMAN NECESSITIES
- A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
- A47G—HOUSEHOLD OR TABLE EQUIPMENT
- A47G19/00—Table service
-
- A—HUMAN NECESSITIES
- A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
- A47G—HOUSEHOLD OR TABLE EQUIPMENT
- A47G21/00—Table-ware
- A47G21/02—Forks; Forks with ejectors; Combined forks and spoons; Salad servers
-
- A—HUMAN NECESSITIES
- A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
- A47G—HOUSEHOLD OR TABLE EQUIPMENT
- A47G33/00—Religious or ritual equipment in dwelling or for general use
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
- C25D5/10—Electroplating with more than one layer of the same or of different metals
- C25D5/12—Electroplating with more than one layer of the same or of different metals at least one layer being of nickel or chromium
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
- C25D5/48—After-treatment of electroplated surfaces
- C25D5/50—After-treatment of electroplated surfaces by heat-treatment
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
- C25D5/627—Electroplating characterised by the visual appearance of the layers, e.g. colour, brightness or mat appearance
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Adornments (AREA)
- Electroplating Methods And Accessories (AREA)
Abstract
ABSTRACT
GOLD COLORED WARE
Decorative-utility objects such as cutlery, plates, bowls and the like are advantageously constructed of an alpha brass or an alpha nickel-silver or cupro-nickel base, an outer plated layer of gold and an intermediate plated layer of nickel. The plated object is then annealed to interdiffuse gold and nickel whereby the gold layer is hardened to give enhanced wear resistance and utility.
GOLD COLORED WARE
Decorative-utility objects such as cutlery, plates, bowls and the like are advantageously constructed of an alpha brass or an alpha nickel-silver or cupro-nickel base, an outer plated layer of gold and an intermediate plated layer of nickel. The plated object is then annealed to interdiffuse gold and nickel whereby the gold layer is hardened to give enhanced wear resistance and utility.
Description
~3~?38~2 .
GOLD COLORED WARE
The present invention is concerned with jewelry, flatware and like items which are generally made of a copper-rich base metal and which have a gold surface.
BACKGROUND OF THE INVENTION
-There is a market for gold surfaced jewelry, flatware, cups, dishes, candle sticks holders, bowls~ platters and the like which are inexpensive but which are of a better quality than the common gold plated items. For purposes of convenience in this specification and claims such items are called 'idecora~ive-utility"
items~.~ Some of the problems in~olved in~producing better quality decorative-utility items ar1se~from~the use of copper-base materials such as~brass, cupro-nickel and nickel-silver as the primary str~uctural materlal of the item. The use of such materials is dictated by cost and by~convenience~in cold forming the item.
However, such copper-base alloys~generally corrode severely in contact with substances commonly found around people and households.
:~ ~
.
~3~?3l~Q~
GOLD COLORED WARE
The present invention is concerned with jewelry, flatware and like items which are generally made of a copper-rich base metal and which have a gold surface.
BACKGROUND OF THE INVENTION
-There is a market for gold surfaced jewelry, flatware, cups, dishes, candle sticks holders, bowls~ platters and the like which are inexpensive but which are of a better quality than the common gold plated items. For purposes of convenience in this specification and claims such items are called 'idecora~ive-utility"
items~.~ Some of the problems in~olved in~producing better quality decorative-utility items ar1se~from~the use of copper-base materials such as~brass, cupro-nickel and nickel-silver as the primary str~uctural materlal of the item. The use of such materials is dictated by cost and by~convenience~in cold forming the item.
However, such copper-base alloys~generally corrode severely in contact with substances commonly found around people and households.
:~ ~
.
~3~?3l~Q~
For example, cartridge brass and nickel-silver are corroded severely by human sweat, aqueous ammonia and sulfides, either airborne or in solution.
A thin layer of gold, perhaps 0.2 to 0.6 micrometer thlck, is sufficient to impart a satisfactory golden appearance to an item ~ade of copper-base alloy. However, a layer of gold that thin gives essentially no corrosion protection to the underlying metal. In fact in aqueous electrolytic systems, e~g. common salt water, a very thin gold surface layer can accelerate corrosion of the underlying metal by providing a built-in~ nicely coupled, cathode-anode system. The copper-base alloy unfortunately serves as the anode and is consumed.
The art has learned to avoid this problem by interposing, between the copper alloy of the base and the gold outer layer, an intermediate layer of nickel of sufficient thickness to inhibit corrosion of the copper alloy base. The use of such an intermediate layer solves the corrosion problem without the use of very thick layers of gold which would be uneconomical. It doesn't solve all the problems however.
Gold is soft and scratches easily. In very thin layers, e.g. 0.3-0.6 micrometer thick, scratches can easily go through to the base and uncover the underlying white nickel. Such scratches then are very unsightly. This problem can be solved by electrodepositing a relatively hard gold alloy instead of gold but this solution is not ideal. First, because of electrochemical factors such as the use of insoluble anodes, it is difficult to plate consistent alloy compositions item to item and batch to batch. Thus, there can be observable differences in appearance between such items and such batches. Secondly, the alloy plate is of uniform hardness through the thickness of the deposit. If the plate deposit is made hard enough to significantly inhibit scratching, there is danger that through internal stress, adhesion to the nickel lnterlayer will be weak~
Applican~ has now provided a process whereby improved gold surfaced decorative-utility items can be produced.
~3~38~Z
_3~ PC-3120 DESCRIPTION OF THE INVENTION
The present invention contemplates a composite material in the form of a "decorative-utility" item, comprising a base made of a metal from the group of copper-base alloys, i.e. alpha brasses, cupro-nickels and alpha nickel-silvers, an intermediate layer of nickel at leas~ about 3 micrometers thick and a surface layer of gold at least about 0.3 micrometer thick up to e.g. about 0.6 micrometer or even 0.8 micrometer thick. The nickel-gold coating can cover the entire surfaces of the decorative-utility item or can be confined to one surface or a portion of the entire surface. The gold contains a varying amount of nickel such that the nickel content decreases from the side of the gold abutting the nickel layer to about 1-10% by weight at the outer surface. The gold layer is metallurgically bonded to the nickel and contains at the outer surface an amount of nickel sufficient to increase the hardness of the gold layer but insufficient to significantly destroy the distinctive color of the gold layer. In some instances, ~ickel as in the inter~ediate layer can serve as the base.
The "decorative-utility" structure of the present invention can be made by depositing, e.g. by electroplating, a layer of gold onto a nickel surfaced base and thereafter annealing the composite structure to provide a metallurgical bond therebetween and to interdiffuse nickel of the intermediate layer and gold o the surface layer.
DETAILS OF THE INVENTION
. .
In order to provide those skilled in the art with greater detail with respect to the present invention, the following paragraphs set forth particulars and alternatives contemplated to be within the scope of the invention as hereinbefore described.
The base of the composlte structure of the present invention is advantageously any alpha brass, i.e. a copper-~inc alloy containing about 5 to about 30% zinc or an alpha nickel~silver, i.e.
an alloy containing greater than 65% nickel plus copper and less than 35% ~inc or a cupro-nickel, i.e. a copper-base alloy containing up ~3~3~3~2 to about 40~ nickel. Cartridge brass which generally contains 30~
zinc, balance copper, nickel-silver which contains about 65% copper, 10 to 18% nickel, balance zinc and cupro-nickel containing 5-40%
nickel, up to 3% iron, balance copper are quite suitable as base materials for the composite structures of the present invention. As those skilled in the art are aware, these metals are supplied in sheet, rod, wire, tube and strip form. Shapes are fabricated from these and other standard forms by stamping, cutting, bending, rolling, drawing, hammering, spinning, machining 7 swaging and other well-known manufacturing techniques. It is within the contemplation of the present invention that the necessary nickel interlayer between the base and the gold outer layer can be applied to a raw or semi-fabricated form of the article and be worked along with the copper-base material. The use of a composite sandwich of copper alloy and nickel is not preferred because of the likelihood of production of edge areas not covered with nickel. ~owever, if such edge areas are not exposed, the use of a composite sandwich will be satisfactory.
There is advantage in providing a nickel deposit on the structure by electrodeposition. While other means of providing a nickel deposit such as chemical deposition, sputtering, ion bombardment, etc. are within the contemplation of the present invention, electroplating has been found to be an easy, reliable method of providing a nickel deposit which is essentially free from organic residue, sulfur and low melting phaæes. The nickel electrodeposit is accomplished by standard procedures using Watts-type, chloride, fluoborate and sulfamate baths such as those disclosed in Electroplating Engineering Handbook, Graham, Van Nostrand-Reinhold, 3rd Ed., 1971, pages 247 and 248.
In most cases, there is no upper limit to the thickness of 3~ a nickel coating or deposit on a structure e~capt that limit which may be imposed by practicality, e.g. about 40 micrometers when nickel is electrodeposited. It is important that the nickel on the surface of the structure be at least about 3 micrometers thick and advantageously in the range of ~ to 12 micrometers in thickness. The nickel layer acts as a barrier coating to diffusion of unwanted elements, e.g. copper and zinc, in the base into the gold and must be .
X
~3~31~2 sufficlently thick to serve this function as well as to provide to the gold the amount of nickel required for hardening.
The gold on the nickel surface of the base is advantageously electrodeposited as pure (24 KT) gold from an electroplating bath using conditions applicable to obtaining a pure electrodeposit. For purposes of this specification and claims, however, gold need not be 100% pure. For purposes of this invention, the term "gold" includes not only pure gold but also yellow alloys and reddish yellow alloys which may contain silver, copper, nickel, a platinum group metal and comb-lnations thereof. Gold containing up to about 8% to 10% by weight nickel will retain its gold color equivalent to the color of 14 KT to 18 KT gold-silver-copper alloy.
The gold layer on the nickel surface of the base i9 advantageously electrodeposited from a cyanide type bath. Such baths are usually of proprietary nature. However, the general types of cyanide baths and conditions of operation are set forth in standard reference sources such as Electroplating Engineering Handbook IBID, page 242 and in References 1, 2, 29, 30, 31, 32 and 33 listed on page 255 of that work. It is also within the contemplation of the present invention to provide gold layers of the requisite thickness by means other than electroplating provided, of course, that the quality of the adhesion of the gold layer to the nickel is at least equivalent to that provided by electroplating. As those skilled in the art are aware, the quality of adhesion of an electroplate depends to a large extent on the care taken in surface preparation and cleaning of the base to be plated. In this regard Chapter 3 of the aforecited Electroplating Engineering ~andbook entitled "Metal Surface Preparation and Cleaning" is recommended to those desiring to practice ehe present invention.
In producing the composite structure of the present invention, the annealing step to achieve the metallurgical bond between gold and nickel and to harden the gold is an important feature. Annealing can be carried out any time after deposition of the gold layer, either before or after working or mechanical operation on the composite material. The conditions of temperature and time of annealing are selected so that an interdiffused layer of gold and nickel is achieved without loss of the desired surface ~3~J`3B(~
~6- PC-3120 color. For example, with a gold deposit averaging 0.5 micrometers thick, effective annealing in hydrogen at 450C may be achieved in a short time, e.g. in the range of about 4 to 25 minutes. This annealing time has been determined as residence time in a 5 cm tube furnace under laboratory conditions. Those skilled in the art will appreciate that commercial scale furnacing can vary in temperature and time. Annealing to interdiffuse nickel and gold must be carried out in such a fashion so as to avoid detrimental dissipation of strength induced in the coated ob~ect by cold working. Various copper-base alloys as set forth in the following table have ranges of annealing temperature which are employed for softening the alloys after cold working operations.
TABLE
Composition (% by Wt) Alloy Cu Zn Ni Other Annealing Range (C) Jewelry Bronze 87.5 12.5 -- -- 425-750 Red Brass 85 15 -- -- 425-750 : Cartridge Brass 70 30 -- -- 425-750 Nickel-Silver 65-18 65 1718 -- 593-815 Nickel-Silver 55-18 55 2718 ~- 593-815 Nickel-Silver 65-12 65 2312 -- 593-815 Cupro-Nickel 10% 88.7 ~- 10 1.3Fe 650-815 Cupro-Nickel 30% 70 -- 30 -- 600-815 A typical full annealing treatment for cartridge brass cold drawn 50%
involves heating for one hour at a temperature of about 425~C to about 540C. A decorative-utility object made of cartridge brass should be annealed for nickel-gold interdiffusion at a time at temperature generally which is less than that which will achieve full softening of work-hardened brass. The softening annealing range applicable to the nickel-silvers and cupro-nickels makes these alloys more amenable to use in the present invention because the gold-nickel interdiffusion heat treatment has less softening effect on the work-hardened nickel-silver.
In order to give those skilled in the art a greater appreciation of the advan~agss of the present invention the following examples are given:
~3~3t~)Z
EXAMPLES
Copper-base alloys in the forms of ~utlery items, e.g.
forks and spoons and plates, costume jewelry and emblems are provided. These are made of nickel-silver 65-12, jewelry bronze, c~pro-nickel 10% and cartrldge brass. The items are thoroughly cleaned and degreased and then electroplated in a Watts-type bath with 10 micrometers of nickel followed after thorough rinsing, by plating 0.5 micrometer of 24 KT gold from a proprietary complex cyanide electroplating bath. Following plating, the rinsed and thoroughly dry items are heat treated in an inert atmosphere as set forth in the following ~able.
TABLE
Alloy of Item Time Temperature Jewelry Bronze 15 min 450C
Cartridge Brass 15 min 450C
Cupro-Nickel 10~ 25 min 450C
Nickel-Silver 65-12 25 min 500C
In each instance, the final plated and heat treated items have an attractive gold colored finish which is significantly harder and more wear resistant than similar items plated with gold in the manner customary in the trade. Because of their longer time heat treatment at higher temperature, the items having a base of nickel-silver are somewhat whiter in tinge than the other items in the preceding table but are definitely of a golden color normally associated with yellow 14 KT gold.
While in accordance with the provisions of the statute, there is illustrated and described herein specific embodiments of the invention, those skilled in the art will understand that changes may be made in the form of the invention covered by the claims and that certain features of the invention may sometlmes be used to advantage without a corresponding use of the other features.
A thin layer of gold, perhaps 0.2 to 0.6 micrometer thlck, is sufficient to impart a satisfactory golden appearance to an item ~ade of copper-base alloy. However, a layer of gold that thin gives essentially no corrosion protection to the underlying metal. In fact in aqueous electrolytic systems, e~g. common salt water, a very thin gold surface layer can accelerate corrosion of the underlying metal by providing a built-in~ nicely coupled, cathode-anode system. The copper-base alloy unfortunately serves as the anode and is consumed.
The art has learned to avoid this problem by interposing, between the copper alloy of the base and the gold outer layer, an intermediate layer of nickel of sufficient thickness to inhibit corrosion of the copper alloy base. The use of such an intermediate layer solves the corrosion problem without the use of very thick layers of gold which would be uneconomical. It doesn't solve all the problems however.
Gold is soft and scratches easily. In very thin layers, e.g. 0.3-0.6 micrometer thick, scratches can easily go through to the base and uncover the underlying white nickel. Such scratches then are very unsightly. This problem can be solved by electrodepositing a relatively hard gold alloy instead of gold but this solution is not ideal. First, because of electrochemical factors such as the use of insoluble anodes, it is difficult to plate consistent alloy compositions item to item and batch to batch. Thus, there can be observable differences in appearance between such items and such batches. Secondly, the alloy plate is of uniform hardness through the thickness of the deposit. If the plate deposit is made hard enough to significantly inhibit scratching, there is danger that through internal stress, adhesion to the nickel lnterlayer will be weak~
Applican~ has now provided a process whereby improved gold surfaced decorative-utility items can be produced.
~3~38~Z
_3~ PC-3120 DESCRIPTION OF THE INVENTION
The present invention contemplates a composite material in the form of a "decorative-utility" item, comprising a base made of a metal from the group of copper-base alloys, i.e. alpha brasses, cupro-nickels and alpha nickel-silvers, an intermediate layer of nickel at leas~ about 3 micrometers thick and a surface layer of gold at least about 0.3 micrometer thick up to e.g. about 0.6 micrometer or even 0.8 micrometer thick. The nickel-gold coating can cover the entire surfaces of the decorative-utility item or can be confined to one surface or a portion of the entire surface. The gold contains a varying amount of nickel such that the nickel content decreases from the side of the gold abutting the nickel layer to about 1-10% by weight at the outer surface. The gold layer is metallurgically bonded to the nickel and contains at the outer surface an amount of nickel sufficient to increase the hardness of the gold layer but insufficient to significantly destroy the distinctive color of the gold layer. In some instances, ~ickel as in the inter~ediate layer can serve as the base.
The "decorative-utility" structure of the present invention can be made by depositing, e.g. by electroplating, a layer of gold onto a nickel surfaced base and thereafter annealing the composite structure to provide a metallurgical bond therebetween and to interdiffuse nickel of the intermediate layer and gold o the surface layer.
DETAILS OF THE INVENTION
. .
In order to provide those skilled in the art with greater detail with respect to the present invention, the following paragraphs set forth particulars and alternatives contemplated to be within the scope of the invention as hereinbefore described.
The base of the composlte structure of the present invention is advantageously any alpha brass, i.e. a copper-~inc alloy containing about 5 to about 30% zinc or an alpha nickel~silver, i.e.
an alloy containing greater than 65% nickel plus copper and less than 35% ~inc or a cupro-nickel, i.e. a copper-base alloy containing up ~3~3~3~2 to about 40~ nickel. Cartridge brass which generally contains 30~
zinc, balance copper, nickel-silver which contains about 65% copper, 10 to 18% nickel, balance zinc and cupro-nickel containing 5-40%
nickel, up to 3% iron, balance copper are quite suitable as base materials for the composite structures of the present invention. As those skilled in the art are aware, these metals are supplied in sheet, rod, wire, tube and strip form. Shapes are fabricated from these and other standard forms by stamping, cutting, bending, rolling, drawing, hammering, spinning, machining 7 swaging and other well-known manufacturing techniques. It is within the contemplation of the present invention that the necessary nickel interlayer between the base and the gold outer layer can be applied to a raw or semi-fabricated form of the article and be worked along with the copper-base material. The use of a composite sandwich of copper alloy and nickel is not preferred because of the likelihood of production of edge areas not covered with nickel. ~owever, if such edge areas are not exposed, the use of a composite sandwich will be satisfactory.
There is advantage in providing a nickel deposit on the structure by electrodeposition. While other means of providing a nickel deposit such as chemical deposition, sputtering, ion bombardment, etc. are within the contemplation of the present invention, electroplating has been found to be an easy, reliable method of providing a nickel deposit which is essentially free from organic residue, sulfur and low melting phaæes. The nickel electrodeposit is accomplished by standard procedures using Watts-type, chloride, fluoborate and sulfamate baths such as those disclosed in Electroplating Engineering Handbook, Graham, Van Nostrand-Reinhold, 3rd Ed., 1971, pages 247 and 248.
In most cases, there is no upper limit to the thickness of 3~ a nickel coating or deposit on a structure e~capt that limit which may be imposed by practicality, e.g. about 40 micrometers when nickel is electrodeposited. It is important that the nickel on the surface of the structure be at least about 3 micrometers thick and advantageously in the range of ~ to 12 micrometers in thickness. The nickel layer acts as a barrier coating to diffusion of unwanted elements, e.g. copper and zinc, in the base into the gold and must be .
X
~3~31~2 sufficlently thick to serve this function as well as to provide to the gold the amount of nickel required for hardening.
The gold on the nickel surface of the base is advantageously electrodeposited as pure (24 KT) gold from an electroplating bath using conditions applicable to obtaining a pure electrodeposit. For purposes of this specification and claims, however, gold need not be 100% pure. For purposes of this invention, the term "gold" includes not only pure gold but also yellow alloys and reddish yellow alloys which may contain silver, copper, nickel, a platinum group metal and comb-lnations thereof. Gold containing up to about 8% to 10% by weight nickel will retain its gold color equivalent to the color of 14 KT to 18 KT gold-silver-copper alloy.
The gold layer on the nickel surface of the base i9 advantageously electrodeposited from a cyanide type bath. Such baths are usually of proprietary nature. However, the general types of cyanide baths and conditions of operation are set forth in standard reference sources such as Electroplating Engineering Handbook IBID, page 242 and in References 1, 2, 29, 30, 31, 32 and 33 listed on page 255 of that work. It is also within the contemplation of the present invention to provide gold layers of the requisite thickness by means other than electroplating provided, of course, that the quality of the adhesion of the gold layer to the nickel is at least equivalent to that provided by electroplating. As those skilled in the art are aware, the quality of adhesion of an electroplate depends to a large extent on the care taken in surface preparation and cleaning of the base to be plated. In this regard Chapter 3 of the aforecited Electroplating Engineering ~andbook entitled "Metal Surface Preparation and Cleaning" is recommended to those desiring to practice ehe present invention.
In producing the composite structure of the present invention, the annealing step to achieve the metallurgical bond between gold and nickel and to harden the gold is an important feature. Annealing can be carried out any time after deposition of the gold layer, either before or after working or mechanical operation on the composite material. The conditions of temperature and time of annealing are selected so that an interdiffused layer of gold and nickel is achieved without loss of the desired surface ~3~J`3B(~
~6- PC-3120 color. For example, with a gold deposit averaging 0.5 micrometers thick, effective annealing in hydrogen at 450C may be achieved in a short time, e.g. in the range of about 4 to 25 minutes. This annealing time has been determined as residence time in a 5 cm tube furnace under laboratory conditions. Those skilled in the art will appreciate that commercial scale furnacing can vary in temperature and time. Annealing to interdiffuse nickel and gold must be carried out in such a fashion so as to avoid detrimental dissipation of strength induced in the coated ob~ect by cold working. Various copper-base alloys as set forth in the following table have ranges of annealing temperature which are employed for softening the alloys after cold working operations.
TABLE
Composition (% by Wt) Alloy Cu Zn Ni Other Annealing Range (C) Jewelry Bronze 87.5 12.5 -- -- 425-750 Red Brass 85 15 -- -- 425-750 : Cartridge Brass 70 30 -- -- 425-750 Nickel-Silver 65-18 65 1718 -- 593-815 Nickel-Silver 55-18 55 2718 ~- 593-815 Nickel-Silver 65-12 65 2312 -- 593-815 Cupro-Nickel 10% 88.7 ~- 10 1.3Fe 650-815 Cupro-Nickel 30% 70 -- 30 -- 600-815 A typical full annealing treatment for cartridge brass cold drawn 50%
involves heating for one hour at a temperature of about 425~C to about 540C. A decorative-utility object made of cartridge brass should be annealed for nickel-gold interdiffusion at a time at temperature generally which is less than that which will achieve full softening of work-hardened brass. The softening annealing range applicable to the nickel-silvers and cupro-nickels makes these alloys more amenable to use in the present invention because the gold-nickel interdiffusion heat treatment has less softening effect on the work-hardened nickel-silver.
In order to give those skilled in the art a greater appreciation of the advan~agss of the present invention the following examples are given:
~3~3t~)Z
EXAMPLES
Copper-base alloys in the forms of ~utlery items, e.g.
forks and spoons and plates, costume jewelry and emblems are provided. These are made of nickel-silver 65-12, jewelry bronze, c~pro-nickel 10% and cartrldge brass. The items are thoroughly cleaned and degreased and then electroplated in a Watts-type bath with 10 micrometers of nickel followed after thorough rinsing, by plating 0.5 micrometer of 24 KT gold from a proprietary complex cyanide electroplating bath. Following plating, the rinsed and thoroughly dry items are heat treated in an inert atmosphere as set forth in the following ~able.
TABLE
Alloy of Item Time Temperature Jewelry Bronze 15 min 450C
Cartridge Brass 15 min 450C
Cupro-Nickel 10~ 25 min 450C
Nickel-Silver 65-12 25 min 500C
In each instance, the final plated and heat treated items have an attractive gold colored finish which is significantly harder and more wear resistant than similar items plated with gold in the manner customary in the trade. Because of their longer time heat treatment at higher temperature, the items having a base of nickel-silver are somewhat whiter in tinge than the other items in the preceding table but are definitely of a golden color normally associated with yellow 14 KT gold.
While in accordance with the provisions of the statute, there is illustrated and described herein specific embodiments of the invention, those skilled in the art will understand that changes may be made in the form of the invention covered by the claims and that certain features of the invention may sometlmes be used to advantage without a corresponding use of the other features.
Claims (7)
1. A decorative-utility object comprising a composite material having on at least a portion of a nickel-surfaced base an outer layer of gold about 0.3 to about 0.8 micrometer thick said outer layer of gold containing nickel decreasing in concentration outwardly to about 1% to about 10% by weight of nickel at the surface.
2. A decorative-utility object as in claim 1 wherein said base is a copper-base alloy selected from the group of alpha brasses, cupro-nickels and alpha nickel-silvers and an intermediate layer of nickel at least about 3 micrometers thick is positioned between and bonded to said base and said gold.
3. A decorative-utility object as in claim 2 wherein the outer gold layer is about 0.5 micrometer thick.
4. A decorative-utility object as in claim 2 wherein the intermediate nickel layer is about 6 to about 12 micrometers thick.
5. A decorative-utility object as in claim 2 having a base of work-hardened alpha brass.
6. A decorative-utility object as in claim 2 having a base of work-hardened nickel-silver.
7. A decorative-utility object as in claim 2 having a base of work-hardened cupro-nickel.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000533536A CA1303802C (en) | 1987-04-01 | 1987-04-01 | Gold colored ware |
| DE3810566A DE3810566A1 (en) | 1987-04-01 | 1988-03-29 | ARTICLE WITH DECORATIVE SURFACE |
| GB8807498A GB2202864B (en) | 1987-04-01 | 1988-03-29 | Gold colored ware |
| FR8804184A FR2615795A1 (en) | 1987-04-01 | 1988-03-30 | ARTICLE WITH GOLD SURFACE |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000533536A CA1303802C (en) | 1987-04-01 | 1987-04-01 | Gold colored ware |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1303802C true CA1303802C (en) | 1992-06-23 |
Family
ID=4135345
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000533536A Expired - Lifetime CA1303802C (en) | 1987-04-01 | 1987-04-01 | Gold colored ware |
Country Status (4)
| Country | Link |
|---|---|
| CA (1) | CA1303802C (en) |
| DE (1) | DE3810566A1 (en) |
| FR (1) | FR2615795A1 (en) |
| GB (1) | GB2202864B (en) |
Family Cites Families (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE895234C (en) * | 1942-03-31 | 1953-11-02 | Degussa | Process for the production of metallic objects, such as jewelry, table equipment, etc. like |
| GB934559A (en) * | 1961-09-12 | 1963-08-21 | Dreher Manfrid | Method of preparing an age-hardened coated metal alloy article |
| GB1008014A (en) * | 1962-03-08 | 1965-10-22 | Standard Telephones Cables Ltd | Method to heat metals for evaporation purposes and/or for diffusion |
| FR1495787A (en) * | 1965-10-22 | 1967-12-20 | ||
| DE2348635C2 (en) * | 1973-09-27 | 1975-09-18 | Hirotsugu Fukui Kimura (Japan) | Process for the production of a base material for spectacle frames |
| CA1015905A (en) * | 1974-09-16 | 1977-08-23 | Arthur G. Mcmullen | Nickel clad steel coinage blank |
| GB1602041A (en) * | 1978-02-09 | 1981-11-04 | Burr Brown Res Corp | Gold plating process |
| US4397086A (en) * | 1981-01-26 | 1983-08-09 | The Bendix Corporation | Method of fabricating a socket type electrical contact |
| JPS6217790Y2 (en) * | 1981-04-15 | 1987-05-08 | ||
| JPS5896890A (en) * | 1981-12-04 | 1983-06-09 | Citizen Watch Co Ltd | Treatment of material plated with gold under heating |
| US4475991A (en) * | 1983-03-25 | 1984-10-09 | Chugai Denki Kogyo K.K. | Method of diffusion cladding a Fe-containing base material for decorative articles and ornaments with precious metal constituents including Ag |
| GB2138027B (en) * | 1983-04-12 | 1986-09-10 | Citizen Watch Co Ltd | A process for plating an article with a gold-based alloy and an alloy therefor |
| DE3473577D1 (en) * | 1983-06-13 | 1988-09-29 | Inco Ltd | Composite material and the production thereof |
| US4551184A (en) * | 1983-06-13 | 1985-11-05 | Inco Limited | Process for obtaining a composite material and composite material obtained by said process |
| US4505060A (en) * | 1983-06-13 | 1985-03-19 | Inco Limited | Process for obtaining a composite material and composite material obtained by said process |
| GB2147612B (en) * | 1983-09-29 | 1986-10-22 | Suwa Seikosha Kk | Method of producing timepiece dial |
| DE3501163A1 (en) * | 1984-01-17 | 1985-08-14 | Nippon Gakki Seizo K.K., Hamamatsu, Shizuoka | Multi-layer material for spectacle frames |
| DE3522656A1 (en) * | 1985-06-25 | 1987-01-08 | Ver Deutsche Metallwerke Ag | Production of coin blanks |
| JPH0615273B2 (en) * | 1986-01-20 | 1994-03-02 | 株式会社アイテイテイキャノン | IC card |
| CA1270408A (en) * | 1987-04-07 | 1990-06-19 | James Alexander Evert Bell | Coated article having a base of age-hardened metal |
-
1987
- 1987-04-01 CA CA000533536A patent/CA1303802C/en not_active Expired - Lifetime
-
1988
- 1988-03-29 DE DE3810566A patent/DE3810566A1/en not_active Withdrawn
- 1988-03-29 GB GB8807498A patent/GB2202864B/en not_active Expired - Fee Related
- 1988-03-30 FR FR8804184A patent/FR2615795A1/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| GB2202864A (en) | 1988-10-05 |
| GB8807498D0 (en) | 1988-05-05 |
| GB2202864B (en) | 1991-10-30 |
| DE3810566A1 (en) | 1988-11-10 |
| FR2615795A1 (en) | 1988-12-02 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |