JP2826201B2 - Money, money blank, medallion, medallion blank, token, token blank, tag or tag blank having luster and appearance of copper and method of manufacturing the same - Google Patents

Abstract

An electroplated blank is disclosed capable of having insignia minted on at least one face to form coins, medallions or tokens, the blank comprising a metallic core e.g. of steel, with an electroplated coating comprising 0.5 to 8% by weight tin, the balance copper, completely enveloping said blank and having a thickness of from about 5 mu m to about 50 mu m.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to metal alloy coins, medallions or tokens and to blanks used for the production of coins, medallions or tokens. More particularly, the present invention relates to such coins, medallions or tokens, and to blanks having improved abrasion resistance compared to copper coins while preserving the luster and appearance of the copper used for their production.

[0002]

2. Description of the Related Art In recent years, the rise in the price of metal for money production has led many countries to promote the production of relatively inexpensive alloy coins in an effort to reduce production costs. Various alloys of copper and zinc have been used with varying success with nickel, aluminum and other metals.

The integrity of money is often judged by its appearance by the general public and is expected to have a gold, silver or copper luster depending on its face value. It is important that the currency does not discolor or otherwise corrode over time. In addition to avoiding these undesirable features, any new currency must have acceptable weight and must have electrical and magnetic properties to be acceptable for use in vending machines.

[0004] Other requirements for new alloy coins are:
Not easily counterfeited, have specific properties to the money sorting machine, have sufficient surface hardness to avoid excessive wear, and at the same time have good stamping
ssion) and inexpensive.

[0005] Canadian Patent No. 1,219,7, issued March 31, 1987
U.S. Pat.No. 4,579,761 issued on Apr. 1, 1986 to Golden Currency or Gold Currency with an electroplated coating containing about 8 to 16%, preferably about 11 to 14% tin and the balance copper. A method for producing a money blank is disclosed. The thickness of the coating on the core surface should be about 10 to 150
μm, preferably 30 to 50 μm. The money and the blank have a golden appearance and are suitable as a substitute for gold coins.

[0006] Because refined copper is expensive, the pure copper or copper alloy coins currently in use are expensive, and the money casting margin, ie, the difference between the par value of the coin and its production cost is small or deficit. It is. Attempts to deposit pure copper on low cost cores in the past have shown that this is to make money prone to corrosion and wear problems. It was believed that such copper particles were coarse, the porosity of the plating deposits, and the inherent low abrasion resistance.

[0007]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a currency which has a suitable copper luster and appearance as a substitute for copper coins and which is relatively inexpensive to produce. It is an object of another aspect of the present invention to provide a copper alloy currency having suitable weight and wear characteristics for a currency operated vending machine.

[0008]

SUMMARY OF THE INVENTION In accordance with the present invention, Applicants provide a low tin bronze alloy having a finer particle deposit and thus adhered to a steel blank having better corrosion and wear resistance. It is believed that the provided tin-copper alloy provides better protection for the steel substrate than pure copper due to a weaker galvanic corrosion couple between the metals and a tighter electrical deposit.

[0009] The above and other objects are attained by engraving.
Engravable, having a first surface that is encased or acceptable
Core made of a metallic material and copper that completely wraps this core
Electroplated coating of tin alloy
At least 5 μm to 50 μm on the first surface.
Coin comprising a coating having a thickness in the range of μm
Bills, money blanks, medallions, medallion blanks,
Token, token blank tag or tag blank
And the copper-tin alloy has a weight of 0 . 5% to 2.1
Contains 2% tin and the balance copper, apart from incidental impurities
A currency having the luster and appearance of copper, characterized by being
Money blank, medallion, medallion blank, toe
Kun, dokun blank, tag or tag blank provided
It was achieved by.

[0010] Such an object should be provided with an engraved seal.
First metal engravable with a metal core having a first surface
And the core is engraved with a copper-tin alloy before engraving
Electroplate and at least 5 μm on the first surface
m to electroplated copper having a thickness of 5 0 .mu.m -
Money, menus that consist of providing a tin alloy coating
Electroplated dallions, tokens, or tags
In the method of manufacturing blanks, electroplating
The deposited on the core copper - 0 tin alloy by weight. 5
% To 2.12 % tin and the balance apart from incidental impurities
Has the luster and appearance of copper characterized by being made of copper
Money, medallions, tokens, or tags
Produced by the method of manufacturing a gas-plated blank .

[0011]

The currency or currency blank according to the invention has a coating which is metallurgically adhered to the core blank and the deposit particles are fine. Therefore, the resistance to corrosion and abrasion is large, and inexpensive metals and alloys can be selected as the core blank, so that the production cost is low.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS The method according to the invention and the products produced thereby will now be described with reference to the following examples and the accompanying drawings. Although the foregoing description and the following examples refer to money blanks, the term `` money '' as used in the specification and claims is intended to include money, medallions and tokens and their blanks. It will be understood that it is intended. Further, in the following examples, the metal material of the core blank is illustrated as low-carbon steel, but, as the metal core material, for example, iron, low-carbon steel,
It is also understood to include stainless steel, nickel, nickel-plated steel, zinc or zinc alloys, copper or various copper alloys containing zinc and / or nickel and / or tin, and suitably pre-treated aluminum or aluminum alloys. Will be.

[0013] The core is advantageously annealed before or after plating, so that the blank with the electroplated coating has a sufficiently low hardness for imprinting. Annealing after electroplating is also advantageous in that it can be used to create a metal bond by interdiffusion between the electroplated low tin copper coating and the core material.

EXAMPLE 1 A batch of edged currency blanks made of low carbon steel and weighing 949 grams was loaded into a rotary horizontal plating barrel with a perforated length of 15 cm and a diameter of 10 cm. Initially, the barrel was passed through a cleaning cycle consisting of a continuous wash of 10% detergent solution, cold water, 10% hydrochloric acid and a second cold water wash. The blank was then immersed in an alkali cyanide bronze plating bath containing copper, tin, potassium hydroxide, potassium cyanide. While maintaining the temperature of the bath between about 55 ° C and 60 ° C, a current of 15 amps was applied to the bath for approximately 1.8 hours.

When removed from the bath, the total weight of the currency blank is 58.7 gram equivalents, the total charge weight of the blank.
It was found to have increased by 5.82%. Wet analysis of the blank indicated that it had a deposit of 2.12% tin by weight. After plating, the currency blanks were annealed at 700 ° C for 15 minutes in a reducing atmosphere in the presence of hydrogen. The money blank was found to have a bronze electrical deposit thickness of approximately 21 μm on its face and approximately 30 μm around its edges. Such coatings were metallurgically bonded to the steel blank, as shown by the microstructures for bronze bonded steel (BBS) and copper bonded steel (CBS) in FIG. 2, respectively, and compared to similarly bonded pure copper. It has been found that it has a fine particle deposit and has improved corrosion and abrasion resistance.

Example 2 Bronze bonded steel (BBS) currency blanks prepared according to the method of the present invention were prepared using copper bonded steel for corrosion and wear resistance.
Evaluated against (CBS) blank and Canadian 1 cent currency blank. Money blanks are 2% Na for corrosion testing
Dipped in a Cl bath and rolled in a rotating drum for abrasion testing. Table 1 shows the parameters of the money test sample.

[0017]

[Table 1]

In the corrosion test, money or blanks are
It was immersed in a 2% NaCl solution for 4 hours. Table 2 shows the results of the corrosion test performed on 10 samples of each blank type.

[Table 2] Black rust spots were found only on copper bonded steel samples. The size of all rust spots was less than 1 mm.

Example 3 A rotary drum abrasion test was performed on 16 samples of each blank type. In this test, the sample was rolled in a rotating cylinder having a rubber lining cloth lining, a hump provided around the sample roll for each rotation, and a charging hole on one side. At the start, the specimens were weighed, immersed in a synthetic sweat solution, and sealed and rotated in a cylinder, but the test cycle was repeated at 100 hour intervals. Three
The cumulative surface thickness loss for the sample as a result of continuing the test up to 00 hours is shown in FIG. The bronze bonded steel samples showed better abrasion resistance than the copper bonded steel blank and Canadian 1 cent sample, but the latter two sample types had similar abrasion resistance over the 300 hour test period.

In general, bronze bonded steel blanks outperformed copper bonded steel blanks in both corrosion and wear tests. The steel core blank was soft enough to create a sharp imprint from the imprint die without excessive wear on the imprint die. The electro-deposited alloy coating exhibited sufficient surface hardness and the mark imprinted thereon did not wear after the long wear test. Although the present invention is particularly suitable for producing currency used as forensic currency, it will be appreciated that it is also useful for the production of medallions, tokens and metal tags. Other embodiments of the invention will be readily apparent to those skilled in the art, and the scope of the invention is given by the appended claims.

[Brief description of the drawings]

FIG. 1 is a graph showing thickness loss as a result of wear over time.

FIG. 2 is a micrograph showing the microstructure of the cross-section of annealed copper bonded steel (CBS) and bronze bonded steel (BBS) produced by the method of the present invention.

──────────────────────────────────────────────────の Continued on the front page (72) Inventor Alan H. Lee Canadian Alberta Tofield Rural route number 4 (no address) (56) References JP-A-61-11895 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C25D 7 / 00-7/12 A44C 21/00 G07F 1/06

Claims (12)

(57) [Claims] 1. Acceptable or acceptable stamped imprint
Made of a stampable metallic material having a first surface
And an electric wire made of copper-tin alloy that completely wraps this core
A coated coating, wherein at least the first
Has a thickness in the range of 5 μm to 50 μm on the surface
Money, money blanks, and medals
On, Medallion Blank, Token, Token Blanc
, Tag or tag blank, the copper-tin alloy
Is 0. by weight. 5% to 2.12 % tin , balance balance
Is copper, apart from incidental impurities
Money, money blank, medario with gloss and appearance
, Medallion blank, token, token blank
Tag, tag or tag blank . 2. The method according to claim 1, wherein the core is iron, low carbon steel, stainless steel, nickel, nickel plated steel, zinc or zinc alloy,
Copper or copper alloy, magnesium or magnesium alloy, or
Money according to 請 Motomeko 1 ing <br/> from pretreated aluminum or aluminum alloy, medallion, token, data
Or blank. 3. The copper-tin alloy is less than 0.5% by weight
Contains 2% tin and the balance is copper apart from incidental impurities
The currency, medallion, toe according to claim 1 or 2, wherein
Kun, tag or blank. 4. The copper-tin alloy contains 2 % tin by weight.
2. The composition according to claim 1, wherein the balance is copper apart from incidental impurities.
Or the currency, medallion, token, tag or
Blank . 5. A first surface to be provided with an imprint.
Forming the lower metal from the first metal that can be engraved and before engraving
The core is electroplated with a copper-tin alloy,
It 5 [mu] m without the Kutomo the first surface 5 0 .mu.m of
Electroplated copper-tin alloy coating with thickness
Money, medallions, and talks that provide
Of electroplated blanks for tags or tags
In the method, depositing on said core by electroplating
The copper-tin alloy has a weight of 0 . 5% to 2.12%
Tin and the remainder consist of copper apart from incidental impurities
Money, medario with copper luster and appearance characterized by
Electroplated brass for tokens, tokens, or tags
Link manufacturing method. 6. The method of claim 5 , wherein the core is subjected to a dilute acid rinse prior to electroplating. 7. The method according to claim 5 , wherein the core is annealed before electroplating. Wherein said prior after electroplating stamped cores are Masa Do baked, consists Rukoto to provide a metallurgical bond between said electroplated coating and the core material according to claim 5, 6 or 7. The method according to 7 . 9. by heating under a reducing atmosphere at about 700 ° C. the electroplated blank to 15 minutes in the presence of a reducing <br/> gas, electric message
9. The method according to claim 8 , wherein the blank blank is annealed before imprinting . 10. Since the reducing gas is hydrogen.
10. The method of claim 9, wherein the method comprises: 11. The copper-tin alloy contains 0.5% by weight.
It contains 2% tin and the remainder, apart from incidental impurities
11. The method according to claim 5, wherein the material is copper.
The described method. 12. The method of claim 1 wherein said copper-tin alloy comprises 2% tin by weight.
Is copper and the remainder is copper apart from incidental impurities?
The method according to any one of claims 5 to 10, comprising: