JPH04362149A - Platinum alloy - Google Patents

Abstract

PURPOSE:To obtain Pt allays having hardness and elasticity necessary for an ornamental material. CONSTITUTION:A Pi alloy is obtd. by incorporating at least 1-3wt.% Nb or Mo, 7-9wt.% Cu is incorporated into this Pt alloy to obtain a Pt alloy and 3-7wt.% Pd is further incorporated into this Pt alloy contg. 7-9wt.% Cu to obtain a Pt alloy.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION The object of the present invention is to provide a platinum alloy which has increased hardness, particularly during annealing, and which also imparts strong elastic force to the platinum alloy.

0002

[Prior Art] Generally, platinum alloys used for jewelry and the like have processing strength and a grade of 850% or higher, in which 850 parts by weight of platinum and 12 parts by weight of palladium are used.
0 parts by weight, alloy consisting of 30 parts by weight of cobalt, platinum 8
50 parts by weight, 80 parts by weight of palladium, 50 parts by weight of copper,
An alloy containing 20 parts by weight of cobalt has been used as the SSP material.

[0003] However, this type of alloy does not necessarily have sufficient hardness and elasticity, and there is a problem in that jewelry rings etc. made of this SSP material are deformed. especially,
This type of alloy had a tendency to be extremely poor in hardness and elasticity during annealing. Furthermore, this type of alloy does not have sufficient elasticity, and is therefore unsuitable for use as a decorative spring material or for forming jewelry that utilizes the elastic deformation of the alloy.

From this point of view, various attempts have been made to use platinum alloys containing tungsten as jewelry materials. A typical example of this platinum alloy containing tungsten is an alloy composition consisting of 90% by weight of platinum, 3% by weight of tungsten, and 7% by weight of copper.

[0005]

[Problems to be Solved by the Invention] The use of tungsten, a group 6 element other than precious metals, as an alloying means for platinum is a very unique attempt as a jewelry material, and it has a hardness and hardness unique to platinum for jewelry. Its purpose was to impart elasticity.

However, in platinum alloys containing tungsten, tungsten, which is an additive element in the alloy, is relatively expensive, and the melting temperature of tungsten is higher than that of molybdenum, etc., making it difficult to cast platinum alloys with desired characteristics. was there.

[0007] In addition, this type of platinum alloy containing tungsten has improved as-cast hardness, working hardness, and annealing hardness compared to the above-mentioned SSP material, and also has improved elasticity, and is superior to conventional platinum alloys. It is said to have much better functional properties than alloys, but with the recent diversification and multifunctionality of jewelry materials, it has become necessary for jewelry materials to meet even higher functional characteristics. There was an inconvenience that it could not be cut.

[0008] Platinum alloys whose functional properties have been improved by tungsten tend to have an extremely poor hardness when subjected to annealing treatment, and the functional properties of jewelry that has been subjected to brazing treatment etc. It was recognized that the characteristics were significantly impaired.

In view of the disadvantages of conventional platinum alloys, the present invention provides easy molding of platinum alloys that have the hardness and elasticity required for jewelry materials, especially platinum alloys that have comparable hardness during annealing. It is an object.

0010

[Means for Solving the Problems] The platinum alloy according to the present invention achieves the above object, and in the invention of claim 1, the platinum alloy formed contains at least 1wt% to 3wt%.
The composition includes t% of niobium or molybdenum.

[0011] Further, in the invention of claim 2, the platinum alloy formed has a composition containing at least 1 wt% to 3 wt% of one of niobium or molybdenum and 7 wt% to 9 wt% of copper.

Furthermore, in the invention of claim 3, the platinum alloy formed includes at least 1 wt% to 3 wt% of niobium or molybdenum, 7 wt% to 9 wt% of copper, and 3 wt% of copper.
The composition includes palladium in an amount of t% to 7wt%.

[0013]

[Example] First, as a platinum alloy of an example according to the invention of claim 1, for platinum with a purity of 99.95%,
The composition is formed to include 0% purity niobium as a group 5 element or molybdenum as a group 6 element in a range of at least 1 wt% to 3 wt%.

[0014] Next, as a platinum alloy of an embodiment according to the invention of claim 2, platinum with a purity of 99.95% was used.
90% pure niobium or molybdenum in the range of at least 1 wt% to 3 wt%, and copper in the range of 7 wt% to 9 wt%.
It is formed as a composition containing within a range of %.

Furthermore, the platinum alloy of the embodiment according to the invention of claim 3 has a purity of 99.90% for platinum with a purity of 99.5%.
% purity of at least 1 type of niobium or molybdenum
Contains copper in the range of wt% to 3wt%, and contains copper in the range of 7wt% to 9wt%.
Contains palladium in the range of wt% and palladium from 3wt% to 7w
It is formed as a composition containing within a range of t%.

[0016] The functional characteristics of the platinum alloy according to the present invention will be clarified below using Examples and Comparative Examples. In order to clarify the functional properties of this platinum alloy, we prepared samples of platinum alloys made of niobium, molybdenum, tungsten, and vanadium, and also prepared SSP materials as conventional platinum alloy materials. We experimented and analyzed its characteristics.

In this experiment, vanadium was used as the Group 5 element and tungsten was used as the Group 6 element, and a platinum alloy with niobium added and a platinum alloy with molybdenum added were used as comparative examples. Furthermore, in order to clarify the range of functional properties of each alloy, comparative examples were prepared in which the addition rate of additional elements to the alloy was 0.1% by weight. In addition, platinum 850 is used as an SSP material.
A platinum alloy containing 120 parts by weight of palladium and 30 parts by weight of cobalt was used.

The sample contains 99.95% pure platinum, 99.90% pure vanadium, or niobium, or molybdenum, or 0.1 wt% of a type of tungsten.
Platinum alloy samples were prepared by adding 1.0 wt% and 3.0 wt%.

[0019] Also, 3.0 wt% of vanadium, niobium, molybdenum, or tungsten with a purity of 99.90% to platinum with a purity of 99.95%,
A platinum alloy sample was prepared by adding 7 wt% of copper.

Furthermore, for platinum with a purity of 99.95%,
2wt% molybdenum with a purity of 99.90%, 8w copper
Samples were prepared of a platinum alloy to which 5 wt% of palladium was added, and a platinum alloy to which 3 wt% of molybdenum, 7 wt% of copper, and 5 wt% of palladium were added to platinum.

Each sample was prepared by wrapping each alloy material in platinum, melting it in a 8 Kva high frequency induction furnace using a quartz crucible, and then cooling it with water to 900° C. in the crucible.

[0022] The as-cast hardness was measured by carving 1.5 mm from the flat surface of the hemispherical sample produced by the above method, polishing the surface with a paper file, and then smoothing the surface with a cloth. The surface was measured using a micro Vickers. The measurement conditions are a load of 100 g, a number of measurement points of 5, and the average value.

To measure the working hardness, each sample prepared by the above method was heated at 100° C. for 10 minutes, annealed and rolled to a thickness of 0.3 mm and a width of 10 mm, and then the measurement load was set to 200 g as described above. It was measured using a micro Vickers in the same manner as above.

[0024] The elastic force was measured by fixing the two rolled samples with a thickness of 0.3 mm, a width of 10 mm, and a length of 25 mm at a 10 mm section in the longitudinal direction, and fixing the other 15 mm sections together. A sample with a tip thickness of 0.5 mm is placed at a point 3 mm from the free end of this sample (Fig. 1).
It was measured by applying a load by touching a wooden board. (See Figure 2) This measurement value is the value obtained by dividing the load applied during bending by the cross-sectional area of the plate, that is, elastic force = load (g) / plate thickness ×
It is expressed in plate width (mm). The maximum load value was defined as the force applied just before the bent portion came into contact with the sample piece on the balance side.

[0025]

[Table 1]

Table 1 shows the as-cast hardness of the platinum alloy samples according to the present example and comparative example. A graph of the as-cast hardness of the platinum alloys shown in Table 1 is shown in FIG. From the graphs in Table 1 and Figure 3, it can be seen that the as-cast hardness of all alloy samples increases compared to the amount of alloying elements added. It has been recognized that it is not possible to provide platinum alloys with sufficient hardness.

[0027]Also, it has been found that platinum alloys with tungsten added and platinum alloys with vanadium added have excellent as-cast hardness with an addition amount of 1 wt% or less;
Platinum alloys with the above addition amount are platinum alloys with niobium added,
Compared to a platinum alloy containing molybdenum, the increase in hardness is gradually reduced, making it impossible to obtain a preferable as-cast hardness.

On the other hand, the addition amount of platinum alloys with niobium addition and platinum alloys with molybdenum addition is 1 wt% to 3 wt%.
It was observed that the as-cast hardness increased linearly between the two, and the synergistic effect when 7 wt% copper was added also provided excellent as-cast hardness to the platinum alloy. It has been found that when niobium and molybdenum are added in an amount of 3 wt% or more, the as-cast hardness increases too much, causing difficulty in workability.

[0029]

[Table 2]

Table 2 shows the measured values of the working hardness of the platinum alloy samples according to the present example and the comparative example. or,
Figure 4 shows the working hardness of the platinum alloys shown in Table 2. Platinum alloys containing 1wt% or less of tungsten exhibit high working hardness, while platinum alloys containing tungsten as an alloying element show high working hardness. There is a tendency for the working hardness to increase and decrease when the amount of tungsten added exceeds 1 wt%, and when the amount of tungsten added exceeds 1 wt%,
Even in the case of ternary alloys containing the above, the rate of increase in working hardness was low, and it was recognized that the hardness characteristics required for recent jewelry materials were difficult.

[0031] Furthermore, the working hardness of platinum alloys containing vanadium is particularly poor, and no improvement in working hardness is observed even at addition rates of 1 wt% or less, and even in ternary alloys containing copper, there is no increase in working hardness. The rate showed a markedly lower trend.

[0032] In platinum alloys with niobium added and platinum alloys with molybdenum added, working hardness tends to increase rapidly when the addition rate is 1 wt% or more, and in ternary alloys with copper, It has been recognized that its processing hardness has been improved, and it can be used in jewelry materials with excellent functional properties. Furthermore, when the addition rate of niobium and molybdenum was 3 wt% or more, the processing hardness was extremely high, the workability was poor, and it was recognized that the material was not suitable for forming jewelry materials by cold working or the like.

[0033] The niobium-added platinum alloy obtained here,
Platinum alloy with molybdenum addition is 900-1,000℃
It is preferable to perform cold working after several times of dulling treatment, and in the case of a thin platinum alloy of about 1 mm, the
Cold working by dulling in seconds. Further, in the case of a platinum alloy containing niobium as an alloying element, after casting, it is preferable to perform a dulling treatment in a high temperature range, particularly in a temperature range of around 1,000°C, and then cold working.

[0034]

[Table 3]

Table 3 shows the elastic properties measured for the platinum alloy samples according to the present example and the comparative example, and is expressed as restoring ability (mm) with respect to elastic force (g/mm). Further, FIG. 5 shows the elastic force of each platinum alloy shown in Table 3.

In the elastic properties shown in Table 3, when the amount of alloying elements added is 1 wt% or less, there is a noticeable difference between platinum alloys with different alloying elements due to the addition of alloying elements. No difference in elasticity was observed.

[0037] On the other hand, the amount of alloying elements added was 3wt%.
A remarkable difference was observed in the elastic properties between the respective platinum alloys when It is recognized that there are differences in elastic properties between the groups of tungsten-added platinum alloys and tungsten-added platinum alloys. That is, it is recognized that niobium-added platinum alloys and molybdenum-added platinum alloys exhibit 1.5 to 2.0 times higher elasticity than vanadium-added platinum alloys and tungsten-added platinum alloys.

[0038]

[Table 4]

Table 4 shows the changes in hardness and elasticity of the platinum alloy samples according to the present example and comparative example, especially the samples containing 7 wt% copper, as well as the changes in hardness and elasticity associated with the dulling treatment of the SSP material. This figure shows the accompanying changes in hardness and elasticity. Furthermore, FIG. 6 shows the change in hardness of each alloy shown in Table 4 due to the dulling treatment, and FIG. 7 is a graph showing the change in elasticity of each alloy shown in Table 4 due to the dulling treatment. It is shown as Table 5 shows the extent of decrease in hardness and elasticity due to the dulling treatment of this platinum alloy.

[0040]

[Table 5]

According to Tables 4 and 5 and the graphs in FIGS. 6 and 7, the hardness of platinum alloys due to dulling treatment is as follows: platinum alloys with niobium, platinum alloys with molybdenum, and platinum with tungsten. It is observed that the reduction value gradually increases in the order of alloy and vanadium-added platinum alloy. In addition, regarding changes in elasticity, it is recognized that the rate of decrease gradually increases in the order of molybdenum-added platinum alloys, niobium-added platinum alloys, tungsten-added platinum alloys, and vanadium-added platinum alloys.

That is, platinum alloys with niobium added and platinum alloys with molybdenum added have little change in hardness and elastic properties due to heat treatment, and are particularly suitable for use in jewelry materials that require functionality. On the other hand, tungsten-added platinum alloys have a high melting point and are difficult to process, and are inferior to niobium-added platinum alloys and molybdenum-added platinum alloys in terms of hardness and elasticity. In addition, there is a disadvantage that the rate of decline in elasticity is large. Furthermore, platinum alloys containing vanadium, which is a member of the same family as niobium, have inferior hardness and elastic properties compared to platinum alloys containing niobium and platinum alloys containing molybdenum, and in particular, the rate of decrease in hardness and elasticity due to dulling treatment is poor. An extremely large inconvenience is recognized.

[0043] It is preferable that the amount of niobium and molybdenum added to the alloy be 1 to 3 wt% in view of the functional properties provided to the platinum alloy formed. If it is less than 1 wt%, sufficient hardness and elasticity will not be obtained, If it exceeds 3 wt%, it becomes too hard.

[0044] Further, the amount of copper added in the above examples is 7 to 9.
wt% is preferable from the metallurgical aspect of the platinum alloy, and 9wt%
If more than % is added, it may become too hard.
There is also the disadvantage that corrosion resistance deteriorates.

[0045] Copper 7 to 10 wt%, molybdenum 3 to 0
A platinum alloy with wt% addition was prepared, and the hardness and elasticity of this platinum alloy were measured in the as-cast state, processed state, and dulled state, and the results were found to be as shown in Tables 6 and 7. The hardness measured in Table 6 was plotted in the graph of Figure 8, and the elasticity measured in Table 7 was plotted in the graph of Figure 9, and when the changes were confirmed, it was found that molybdenum affects the toughness of platinum, and copper hardens platinum. is recognized.

[0046]

[Table 6]

[0047]

[Table 7]

In this Example and Comparative Example, it is recognized that the platinum alloy containing 10 wt % copper is not suitable for practical use due to a significant decrease in hardness and elasticity due to dulling treatment. From this point of view, when a platinum alloy with a grade of 900% is used as a jewelry material, 900Pt-70Cu-30Mo or 900Pt-90Cu-10Mo is preferable for the metal fittings material.

Next, a platinum alloy having a grade of 850% is formed by adding palladium to the molybdenum and niobium-added alloy of the above embodiment. This platinum alloy with a grade of 850% contains 3% palladium compared to the platinum alloy of the above example.
By adding up to 7 wt%, a platinum alloy with better hardness and elasticity than the alloy of the above example can be obtained, and in particular, a platinum alloy with significantly improved elasticity can be obtained.

[0050] The hardness of an example of a platinum alloy containing 7 to 9 wt% copper, 3 to 7 wt% paudium, and 1 to 3 wt% molybdenum as additive alloy materials was measured in comparison with the SSP material, and the following table shows the results. It was recognized that the results were as shown in 8. The hardness in Table 8 is shown in the graph of FIG.

[0051]

[Table 8]

Next, the elasticity of this example is determined by SSP.
The results shown in Table 9 were observed when compared with other materials. The elasticity in Table 9 is shown in the graph of FIG.

[0053]

[Table 9]

[0054] In addition to the platinum alloy containing 7 wt% copper and 3 wt% molybdenum as in the above example, 5 wt% palladium was added.
In the platinum alloy to which wt% was added, no deterioration in hardness or elasticity was observed, and it was observed that the hardness after as-cast and processing became higher, and the elasticity after dulling treatment became significantly better.

[0055]

[Effects of the Invention] Due to the characteristic configuration described above, the present invention uses a platinum alloy with a grade of 900% which has higher hardness and higher elasticity and a platinum alloy with a grade of 850% compared to the conventionally used SSP material (Pt-Co type). % platinum alloy, in particular, by improving the hardness and elasticity during annealing treatment, the reduction in hardness and elasticity of the platinum alloy caused by brazing treatment etc. can be prevented as much as possible. By obtaining a platinum alloy of such high quality and high hardness and elasticity, it has become possible to provide highly functional jewelry.

[Brief explanation of the drawing]

[Figure 1] Perspective view of sample used for elasticity test

[Figure 2] Side view of elasticity measuring device

[Figure 3] Graph showing the amount of added alloy material and as-cast hardness

[Figure 4] Graph showing the amount of additive alloy material added and working hardness

[Figure 5] Graph showing the amount of added alloy material and elastic force

[
Figure 6: Graph showing the as-cast hardness, hardness after processing and dulling of the alloy according to the example

[Fig. 7] Graph showing the elasticity of the alloy according to the example after as-cast, after processing, and after dulling.

[Figure 8] Graph showing the as-cast hardness of the alloy when copper is added as an alloy material, and the hardness after processing and dulling.

[Figure 9] Graph showing the elasticity of the alloy when copper is added as an alloy material after as-cast, after processing, and after dulling.

FIG. 10 is a graph showing the as-cast hardness, hardness after machining, and hardness after dulling of alloys of still other examples and SSP.

[Figure 11] Graph showing elasticity of copper alloy in as-cast state, after processing, and after dulling

Claims (3)

[Claims] 1. A platinum alloy containing at least 1 wt% to 3 wt% of niobium or molybdenum. 2. A platinum alloy comprising at least 1 wt% to 3 wt% of one of niobium or molybdenum and 7 wt% to 9 wt% of copper. 3. A platinum alloy comprising at least 1 wt% to 3 wt% of one of niobium or molybdenum, 7 wt% to 9 wt% copper, and 3 wt% to 7 wt% palladium.