EP0190648A1 - A gold alloy - Google Patents
A gold alloy Download PDFInfo
- Publication number
- EP0190648A1 EP0190648A1 EP86101121A EP86101121A EP0190648A1 EP 0190648 A1 EP0190648 A1 EP 0190648A1 EP 86101121 A EP86101121 A EP 86101121A EP 86101121 A EP86101121 A EP 86101121A EP 0190648 A1 EP0190648 A1 EP 0190648A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- gold
- titanium
- alloy
- temperature
- jewellery
- 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.)
- Withdrawn
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C5/00—Alloys based on noble metals
- C22C5/02—Alloys based on gold
Definitions
- THIS INVENTION relates to a gold alloy.
- the alloy may particularly be used for the production of jewellery, coins or gold bars.
- a gold alloy containing gold and 0.1 to 4.0 % mass by mass (m/m) of titanium.
- the alloy may particularly be used for the production of jewellery, coins or gold bars.
- The. invention extends to a method of manufacturing a gold alloy which includes
- titanium is very suitable to alloy with gold. It has solubilities of about 2.2 % m/m at 1000°C, 1.2% at 800°C and 0.5% at 500°C.
- the hardening phase formed in the solid state is Au 4 Ti.
- one % m/m of titanium in gold represents more than 4 atomic % due to the atomic weights of 48 and 197 which the two metals possess respectively.
- the titanium also gives the gold an attractive lighter yellow colour.
- the alloy preferably has 0.5 to 1.5 % m/m titanium and most preferably has 1 % m/m titanium.
- Titanium fulfils the following requirements that an effective hardening agent for gold with a millesimal finess of 990 should have:
- titanium metal reacts with both oxygen and nitrogen on heating, and is normally covered with a very thin skin of oxide and/or nitride. This skin acts as a barrier and impedes solution of the titanium in the gold during alloy production. Thus the titanium should be in bulk form with minimal surface area.
- the gold and titanium were heated and melted in a ceramic crucible to a temperature of about 1300°C in a medium vacuum which must not be better than 10 -2 Torr or evaporation of the molten gold will occur. Instead of a vacuum, a high quality (99.998% pure) argon protective atmosphere may be used. The melting took place in an induction furnace using a carbon crucible with an inner ceramic lining.
- the melt was cast into a carbon mould at 400°C, again in a medium vacuum.
- the resulting ingot was then held at a temperature of about 800°C for 30 to 60 minutes for solutionising to take place. This was also done in a vacuum.
- the soft alloy obtained after solutionising was then hardened by being held at a temperature of about 500 0 C for about 60 minutes. After hardening in this manner the ingot had a hardness of 180 HV 0.5.
- the hardness of the ingot could be further increased by up to 300 HV 0.5 by cold-working. Reduction to quarter of the original thickness by rolling is tolerated between solutionising treatments.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Adornments (AREA)
- Dental Preparations (AREA)
- Materials For Medical Uses (AREA)
Abstract
An alloy consisting of gold and 0.1 to 4% by weight of titanium.
Description
- THIS INVENTION relates to a gold alloy. The alloy may particularly be used for the production of jewellery, coins or gold bars.
- The quality of fine gold jewellery, coins and small bars is adversely affected by the metal's malleability and low hardness which make its wear resistance very low. When gold is used for jewellery it is thus usually alloyed with metals such as copper, silver, zinc, nickel and palladium. The resultant improvement in mechanical and wear properties is accompanied by poorer chemical properties which lead to corrosion and tarnishing and increase the risk of stress corrosion cracking in alloys with less than 583 millesimal fineness (14 carat). The use of alloys has the advantage, however, of allowing various colours to be produced by incorporating different alloying metals.
- The intrinsic value of jewellery is sometimes an important factor and in Hong Kong, for example, so- called '24-carat' jewellery is very popular and this must have a millesimal fineness of at least 990. There is thus a need for an alloy which has such purity and possesses an acceptable colour and good chemical and mechanical properties and is also amenable to the usual goldsmith's procedures such as soldering, bending, casting, rolling and drawing.
- According to the invention there is provided a gold alloy, containing gold and 0.1 to 4.0 % mass by mass (m/m) of titanium. As indicated above, the alloy may particularly be used for the production of jewellery, coins or gold bars. By incorporation of titanium within the concentration limits claimed, an alloy can be obtained which is harder and therefore more resistant to abrasion, and which is at the same time of a high degree of fineness, and of a desirable bright colour.
- The. invention extends to a method of manufacturing a gold alloy which includes
- melting a suitable amount of gold; and
- dissolving therein a suitable amount of titanium such that the titanium comprises 0.1 to 4.0 % m/m.
- The Applicant has found after extensive experimentation that titanium is very suitable to alloy with gold. It has solubilities of about 2.2 % m/m at 1000°C, 1.2% at 800°C and 0.5% at 500°C. The hardening phase formed in the solid state is Au 4 Ti. Furthermore, one % m/m of titanium in gold represents more than 4 atomic % due to the atomic weights of 48 and 197 which the two metals possess respectively. Fortuitously, the titanium also gives the gold an attractive lighter yellow colour.
- The alloy preferably has 0.5 to 1.5 % m/m titanium and most preferably has 1 % m/m titanium.
- Titanium fulfils the following requirements that an effective hardening agent for gold with a millesimal finess of 990 should have:
- a) be soluble -in molten gold at more than the 1% level;
- b) be soluble at the 1% level in solid gold at a reasonable solutionising temperature (say 800°C);
- c) form a crystallographic hardening phase at a temperature of about 500°C, which has many gold atoms per atom of additive and is thus a highly effective hardening agent; and
- d) have an atomic weight that is much lower than that of gold so that 1% m/m represents a greater atomic %.
- Experimental work has been carried out which shows that a 990 fineness Au/Ti alloy possesses many of the properties required for applications in jewellery manufacture.
- An example of an alloy in accordance with the invention, and its method of manufacture is as follows:-
- 99 grams of gold that was 99.99% pure, was melted with 1 gram of titanium that was 99.7% pure in the form of a rod. Titanium metal reacts with both oxygen and nitrogen on heating, and is normally covered with a very thin skin of oxide and/or nitride. This skin acts as a barrier and impedes solution of the titanium in the gold during alloy production. Thus the titanium should be in bulk form with minimal surface area.
- The gold and titanium were heated and melted in a ceramic crucible to a temperature of about 1300°C in a medium vacuum which must not be better than 10-2 Torr or evaporation of the molten gold will occur. Instead of a vacuum, a high quality (99.998% pure) argon protective atmosphere may be used. The melting took place in an induction furnace using a carbon crucible with an inner ceramic lining.
- The melt was cast into a carbon mould at 400°C, again in a medium vacuum.
- The resulting ingot was then held at a temperature of about 800°C for 30 to 60 minutes for solutionising to take place. This was also done in a vacuum.
- The soft alloy obtained after solutionising was then hardened by being held at a temperature of about 5000C for about 60 minutes. After hardening in this manner the ingot had a hardness of 180 HV 0.5.
- The hardness of the ingot could be further increased by up to 300 HV 0.5 by cold-working. Reduction to quarter of the original thickness by rolling is tolerated between solutionising treatments.
Claims (12)
1. A gold alloy containing from 0.1 to 4 % m/m titanium, the balance being gold.
2. The alloy claimed in Claim 1 in which the titanium is 0.5 to 1.5 % m/m.
3. The alloy claimed in Claim 1 containing 1 % m/m titanium, the balance being gold.
4. An item of jewellery which is of an alloy as claimed in any one of the preceding claims.
5. A coin which is of an alloy as claimed in any one of Claims 1 to 3.
6. A gold bar which is of an alloy as claimed in any one of Claims 1 to 3.
7. A method of manufacturing a gold alloy which includes
melting a suitable amount of gold; and
dissolving therein a suitable amount of titanium such that the titanium comprises 0.1 to 4.0 % m/m.
8. The method claimed in Claim 7, in which the titanium is dissolved in the gold in a vacuum.
9. The method claimed in Claim 7, in which the titanium is dissolved in the gold under an inert atmosphere.
10. The method claimed in Claim 7, in which the titanium is added to the gold in bulk form.
11. The method claimed in Claim 7, in which the molten gold and titanium dissolved therein is cooled to a temperature of about 800°C and held at this temperature for about 30 to 60 minutes.
12. The method claimed in Claim 7, which includes age hardening at a temperature of about 500°C for a period of about 60 minutes.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19853502914 DE3502914A1 (en) | 1985-01-29 | 1985-01-29 | USE OF TITANIUM GOLD ALLOYS |
DE3502914 | 1985-01-29 |
Publications (1)
Publication Number | Publication Date |
---|---|
EP0190648A1 true EP0190648A1 (en) | 1986-08-13 |
Family
ID=6261050
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP86101121A Withdrawn EP0190648A1 (en) | 1985-01-29 | 1986-01-28 | A gold alloy |
Country Status (7)
Country | Link |
---|---|
EP (1) | EP0190648A1 (en) |
JP (1) | JPS61217542A (en) |
DE (1) | DE3502914A1 (en) |
ES (1) | ES8704551A1 (en) |
GR (1) | GR860237B (en) |
PT (1) | PT81919B (en) |
ZA (1) | ZA86637B (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0399721A1 (en) * | 1989-05-26 | 1990-11-28 | THE GENERAL ELECTRIC COMPANY, p.l.c. | Electrical conductors and methods of making them |
DE4439793C1 (en) * | 1994-11-08 | 1995-10-26 | Degussa | Prodn. of cast moulded pieces made of gold@-titanium@ alloy |
EP0685565A1 (en) * | 1993-09-06 | 1995-12-06 | Mitsubishi Materials Corporation | Golden ornament material hardened by alloying with minor components |
US5833462A (en) * | 1995-02-25 | 1998-11-10 | Degussa Aktiengesellschaft | Precision attachments for dental technology capable of being cast on |
US5853661A (en) * | 1994-07-05 | 1998-12-29 | Cendres Et Metaux Sa | High gold content bio--compatible dental alloy |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3709972A1 (en) * | 1987-03-26 | 1988-10-06 | Holzer Walter | GOLD JEWELRY ALLOY |
JPH02185933A (en) * | 1989-01-12 | 1990-07-20 | Agency Of Ind Science & Technol | Gold alloy capable of blackening and treatment therefor |
JPH02225655A (en) * | 1989-02-28 | 1990-09-07 | Agency Of Ind Science & Technol | Gold alloy capable of coloring into bright black color and coloring method therefor |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB876887A (en) * | 1957-07-12 | 1961-09-06 | Degussa | Gold alloys, for use as material for electric resistances |
DE2302837A1 (en) * | 1973-01-20 | 1974-08-01 | Th Wieland Scheideanstalt Dr | Gold platinum palladium alloys - for dental surgery, contg. titanium for high hardness and stiffness |
-
1985
- 1985-01-29 DE DE19853502914 patent/DE3502914A1/en not_active Ceased
-
1986
- 1986-01-27 JP JP61013942A patent/JPS61217542A/en active Pending
- 1986-01-28 ES ES551292A patent/ES8704551A1/en not_active Expired
- 1986-01-28 GR GR860237A patent/GR860237B/en unknown
- 1986-01-28 PT PT81919A patent/PT81919B/en unknown
- 1986-01-28 ZA ZA86637A patent/ZA86637B/en unknown
- 1986-01-28 EP EP86101121A patent/EP0190648A1/en not_active Withdrawn
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB876887A (en) * | 1957-07-12 | 1961-09-06 | Degussa | Gold alloys, for use as material for electric resistances |
DE2302837A1 (en) * | 1973-01-20 | 1974-08-01 | Th Wieland Scheideanstalt Dr | Gold platinum palladium alloys - for dental surgery, contg. titanium for high hardness and stiffness |
Non-Patent Citations (2)
Title |
---|
CHEMICAL ABSTRACTS, vol. 81, no. 8, 26th August 1974, page 205, no. 40552k, Columbus, Ohio, US; M. GRAHAM: "Precipitation hardening in gold-titanium alloys", & PROC. ELECTRON MICROSC. SOC. AMER. 1973, 31, 148-9 * |
Dr.phil. M. HANSEN: "Constitution of binary alloys", 2nd edition, 1958, pages 237-239, McGraw-Hill Book Co., Inc., New York, US * |
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0399721A1 (en) * | 1989-05-26 | 1990-11-28 | THE GENERAL ELECTRIC COMPANY, p.l.c. | Electrical conductors and methods of making them |
US5073210A (en) * | 1989-05-26 | 1991-12-17 | The General Electric Company, P.L.C. | Method of making electrical conductors |
EP0685565A1 (en) * | 1993-09-06 | 1995-12-06 | Mitsubishi Materials Corporation | Golden ornament material hardened by alloying with minor components |
EP0685565B1 (en) * | 1993-09-06 | 1999-03-24 | Mitsubishi Materials Corporation | Golden ornament material hardened by alloying with minor components |
US5853661A (en) * | 1994-07-05 | 1998-12-29 | Cendres Et Metaux Sa | High gold content bio--compatible dental alloy |
DE4439793C1 (en) * | 1994-11-08 | 1995-10-26 | Degussa | Prodn. of cast moulded pieces made of gold@-titanium@ alloy |
EP0717118A2 (en) | 1994-11-08 | 1996-06-19 | Degussa Ag | Process for manufacturing gold-titanium alloy castings |
EP0717118A3 (en) * | 1994-11-08 | 1997-01-29 | Degussa | Process for manufacturing gold-titanium alloy castings |
DE4439793C2 (en) * | 1994-11-08 | 2001-05-23 | Degussa | Process for the production of moldings from gold-titanium alloys |
US5833462A (en) * | 1995-02-25 | 1998-11-10 | Degussa Aktiengesellschaft | Precision attachments for dental technology capable of being cast on |
Also Published As
Publication number | Publication date |
---|---|
PT81919A (en) | 1986-02-01 |
DE3502914A1 (en) | 1986-07-31 |
ES8704551A1 (en) | 1987-04-16 |
ES551292A0 (en) | 1987-04-16 |
PT81919B (en) | 1987-11-12 |
JPS61217542A (en) | 1986-09-27 |
GR860237B (en) | 1986-05-30 |
ZA86637B (en) | 1986-09-24 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4165983A (en) | Jewelry alloys | |
US4311522A (en) | Copper alloys with small amounts of manganese and selenium | |
US4260432A (en) | Method for producing copper based spinodal alloys | |
US10323310B2 (en) | Process for making finished or semi-finished articles of silver alloy | |
GB2255348A (en) | Novel silver-based ternary alloy | |
EP1266974B1 (en) | Gold alloys and master alloys for obtaining them | |
CN101218361A (en) | Manufacture of silver-copper-germanium alloy | |
EP1751322B1 (en) | Process for making finished or semi-finished articles of silver alloy comprising copper and germanium | |
US5147469A (en) | Process for producing copper-based alloys having high strength and high electric conductivity | |
WO2007014577A1 (en) | Platinum alloy and method of production thereof | |
EP0190648A1 (en) | A gold alloy | |
KR102486303B1 (en) | Mold materials for casting, and copper alloy materials | |
US4427627A (en) | Copper alloy having high electrical conductivity and high mechanical characteristics | |
GB2418432A (en) | Silver alloy and its production using a master metal | |
WO2002095082A2 (en) | Method of producing silver-copper alloys | |
US4557895A (en) | Yellow gold alloy | |
JPS6231059B2 (en) | ||
US6136108A (en) | Strontium master alloy composition having a reduced solidus temperature and method of manufacturing the same | |
US4247327A (en) | Alloy strengthening by hydridation | |
JP2886818B2 (en) | Method of manufacturing copper alloy for decoration | |
GB2414739A (en) | Process for making finished or semi-finished articles of silver alloy | |
US5368660A (en) | High temperature TiAl2 -based ternary alloys | |
JPH0723530B2 (en) | Decorative Au alloy member having surface hardened layer | |
JPH0770672A (en) | Gold ornament material hardened by alloying with small amount of component | |
GB2352452A (en) | A gold alloy and a process for the manufacture thereof |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT BE CH FR GB IT LI NL SE |
|
17P | Request for examination filed |
Effective date: 19861110 |
|
17Q | First examination report despatched |
Effective date: 19871130 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
|
18D | Application deemed to be withdrawn |
Effective date: 19880412 |
|
RIN1 | Information on inventor provided before grant (corrected) |
Inventor name: GAFNER, GEOFFREY |