U.S. patent application number 10/135170 was filed with the patent office on 2002-11-07 for platinum-iron alloy, especially for jewelry.
This patent application is currently assigned to W.C. Heraeus GmbH & Co. KG. Invention is credited to Baake, Reinhard, Lupton, David, Manhardt, Harald.
Application Number | 20020164264 10/135170 |
Document ID | / |
Family ID | 7683544 |
Filed Date | 2002-11-07 |
United States Patent
Application |
20020164264 |
Kind Code |
A1 |
Baake, Reinhard ; et
al. |
November 7, 2002 |
Platinum-iron alloy, especially for jewelry
Abstract
Platinum--iron alloys that contain 95-96 wt % Pt, 2-3 wt % Fe,
and 20-3 wt % Ru and/or Ir, and are suitable especially for the
fabrication of jewelry.
Inventors: |
Baake, Reinhard; (Krombach,
DE) ; Lupton, David; (Gelnhausen, DE) ;
Manhardt, Harald; (Bruchkobel, DE) |
Correspondence
Address: |
Klaus P. Stoffel, Esq.
Cohen, Pontani, Lieberman & Pavane
Suite 1210
551 Fifth Avenue
New York
NY
10176
US
|
Assignee: |
W.C. Heraeus GmbH & Co.
KG
|
Family ID: |
7683544 |
Appl. No.: |
10/135170 |
Filed: |
April 30, 2002 |
Current U.S.
Class: |
420/466 |
Current CPC
Class: |
A44C 27/003 20130101;
C22C 5/04 20130101 |
Class at
Publication: |
420/466 |
International
Class: |
C22C 005/04 |
Foreign Application Data
Date |
Code |
Application Number |
May 3, 2001 |
DE |
101 21 598.3 |
Claims
We claim:
1. An alloy comprising: 95-96 wt % Pt; 2-3 wt % Fe, and 2-3 wt % of
at least one of Ru and Ir.
2. An alloy as defined in claim 1, wherein the alloy has of 95.2 wt
% Pt, 3 wt % Fe, and 1.8 wt % Ru.
3. An article of jewelry comprising an alloy of 95-96 wt % Pt; 2-3
wt % Fe, and 2-3 wt % of at least one of Ru and Ir.
Description
BACKGROUND OF THE INVENTION
[0001] The invention concerns platinum--iron alloys with an iron
content of 2-4 wt. %, which are suitable especially for the
fabrication of jewelry.
[0002] Pure platinum, like fine gold, is relatively soft and, also
like gold, is used primarily to produce alloys for articles of
jewelry. The platinum content of these kinds of alloys is usually
950/1,000. Typical alloying components are Ru, Cu, and occasionally
Rh and Ir. These elements are relatively expensive (Ru, Ir, Rh) or
have little effect on the strength of the alloy (Cu and Ir). Nickel
is no longer used for this purpose due to the risk of allergic
reactions.
[0003] Therefore, in the jewelry sector, there is a demand for
alloys that are sufficiently strong, easy to work, resistant to
corrosion and physiologically unobjectionable, and that do not add
significant additional cost beyond the price of platinum.
[0004] It is well known that platinum and palladium alloys can be
hardened with elements such as Fe, Co, B, or Si by a special
alloying method, in which intermetallic phases are formed (U.S.
Pat. No. 5,518,556, col. 1, lines 24-30). Hardness values of 300
kp/mm.sup.2 are achieved.
[0005] Platinum--iron--copper alloys that contain 84-96% Pt, 1-10%
Fe, and 1-10% Cu have also been developed (JP Kokai No. 61
[1986]-281,843). Cu is added because it forms an intermetallic
compound with Pt. A similar system with Pt--Ga--Fe has been
proposed (JP Kokai No. 61[1986]-272,333). Furthermore, Pt--Co
alloys have been described, which may also contain 0.5-5% of the
elements W, Mo, Ti, V, and/or iron (JP Kokai No. 61[1986]-034,139).
Pt--Pd alloys with an Re component and up to 3% Ni, Fe, or Co are
also known (JP Kokai No.2[1990]-043,332).
[0006] In addition, inexpensive white gold and yellow gold alloys
with a low gold content are known, which may contain up to 3% iron.
A higher iron content causes tarnishing of the material (U.S. Pat.
Nos. 4,396,578 and 4,446,102).
[0007] JP 61[1986]-076,633 A1 describes alloys from which gemmy
accessories, i.e., products that resemble gems, are fabricated,
which have an especially durable luster after facets have been
ground. The alloys are produced by alloying 0.1-5 wt. % Ru and
2-15% Fe, Ni, and/or Co with Pt--Pd alloys.
[0008] JP 3[1991]-100,159 describes darkened Pt alloys: 3-20% of
one or more of the metals Cu, Fe, Co, and Ti are alloyed with
platinum. The surface is darkened by heat treatment in an oxidizing
atmosphere and then cooling.
SUMMARY AND DESCRIPTION OF THE INVENTION
[0009] According to the present invention, alloys containing 95-96%
Pt, 2-3% Fe, and 2-3% Ru and/or Ir are extremely well suited for
the fabrication of jewelry due to their hardness, workability and
resistance to corrosion.
[0010] The alloys are usually cast from melts under a shielding gas
and then shaped. After shaping, they may be subjected to a heat
treatment, possibly under a shielding gas, to improve their
mechanical properties.
[0011] A relatively large portion of jewelry platinum is used in
wedding bands, which are produced by sawing blanks from tubes and
then further working the blanks by suitable measures, such as
milling, drawing, forging, and polishing.
[0012] Of course, the alloys are suitable for articles of jewelry
in the broader sense, including jewelry worn on the body or on
clothing, such as rings, bangles, and stickpins, as well as such
articles as wristwatches, pocket watches, toothpicks, and
status-symbol items, such as ballpoint pens, letter openers,
pocketknife handles, and the like.
[0013] The following example explains the invention in greater
detail. The percentages in the example as well as those mentioned
previously are percentages by weight.
SPECIFIC EXAMPLE
I. Production and Shaping of a PtFe3.0Ru1.8 Alloy
[0014] 5 kg of PtFe3.0Ru1.8 were melted inductively in an Ar
atmosphere, cast in a Cu ingot mold to form a bar with a cross
section of 45.times.45 mm, forged into a cylindrical bar of
diameter (.O slashed.) 36 mm, and turned to form a hollow cylinder
(outside .O slashed.32 mm, inside .O slashed.22 mm, length 100 mm).
A tube (outside .O slashed.20 mm, wall thickness 1.5 mm) was
produced from the alloy by conventional tube drawing. The material
could be readily worked in every way.
[0015] The invention is not limited by the embodiments described
above which are presented as examples only but can be modified in
various ways within the scope of protection defined by the appended
patent claims.
* * * * *