JPH0452238A - Titanium-containing high silver quality hard silver alloy - Google Patents

Abstract

PURPOSE:To improve the hardness of a silver alloy without losing the excellent characteristics of the silver and to prevent its secular softening by adding specified amounts of Cu, Ni and Ti to silver. CONSTITUTION:This silver alloy contains, by weight, 0.01 to 1.0% Cu, 0.01 to 1.0% Ni and 0.01 to 1.0% Ti, contains, at need, 0.01 to 1.0% Ge and the balance >=97% Ag. This silver alloy has good work hardenability, precipitation hardenability and melting castability and is free from the generation of secular softening. In this alloy, Cu is required for maintaining the functions for preventing the coarsening of the crystals and for increasing the hardness by precipitation hardening a well as for improving the work hardenability, and in the case of less than the lower limit or more than the upper limit, the above effects are made insufficient or deteriorates. As for Ni, the lower limit or above is required for refining the crystals and increasing the hardness, and in the case of more than the upper limit, the melting castability deteriorates. As for Ti, the lower limit or above is required for promoting the work hardenability and precipitation hardenability, and in the case of more than the upper limit, the workability and melting castability deteriorate.

Description

[Detailed description of the invention] <Industrial application field> The disclosed technology belongs to the field of silver alloy composition technology.

<Summary of the gist> As described above, the invention of this application relates to a high silver grade hard silver alloy, and in particular, the invention relates to a high silver grade hard silver alloy, and in particular, the invention relates to a hard silver alloy with a weight ratio of 0.01% to 1% copper.
．． 0%, nickel 0.01% to 1.0%.

This invention relates to a titanium-containing high silver grade hard silver alloy having a composition of 0.01% to 1.0% titanium, further 0.01% to 1.0% germanium, and 97% or more high silver.

<Prior Art> As is well known, silver is widely used in coins, silverware, jewelry, etc. because of its visually silvery white color tone and good workability when making products.

Furthermore, due to its physical properties such as low electrical resistance and high thermal conductivity, and its chemical properties such as excellent oxidation resistance, it is often used industrially in various fields such as electrical contacts. .

In particular, coins, silverware, jewelry, etc. are made by the lost wax method or mechanical processing, and high-grade silver alloys are widely used as the material.

<Problems to be Solved by the Invention> However, the conventional high-grade silver alloy has extremely low hardness, easily softens over time, has coarse crystals, and is difficult to process during processing. There were disadvantages such as damage to the product and wear caused by minute scratches during use of the product.

<Object of the Invention> The object of the invention of this application is to solve the technical problems of high-silver-grade silver alloys based on the above-mentioned prior art, which have good work hardenability, do not soften over time, and, in addition, An object of the present invention is to provide an excellent titanium-containing high-silver-grade hard silver alloy that has good melting and casting properties so that it can be used not only for jewelry but also for a wide range of industrial purposes, thereby benefiting processing technology applications in the metal industry. It is.

<Means/effects for solving the problem> In order to solve the above-mentioned problem, the structure of the invention of this application, which is based on the scope of the above-mentioned patent claims, is to solve the above-mentioned problem by adding copper, nickel, and titanium each in weight ratio. 0.01%~1.
0%, or even germanium 0.01% to 1.0%, and a high silver grade hard silver alloy with a high silver content of 97% or more, which can be easily processed by the lost wax method and machining, and has good work hardening properties.
It has good precipitation hardenability, excellent melting and casting properties, grain refinement, and technical measures have been taken to prevent softening over time and wear and tear of the final product.

<Principle Background of the Invention> The reason for the limitations on the mixing ratio of each additive element in the structure of the above-mentioned claims can be qualitatively and quantitatively explained based on experiments as follows. .

First, regarding copper, it is necessary not only to prevent coarsening of crystals and to maintain the function of increasing hardness through precipitation hardening, but also to increase work hardenability.
It has been confirmed that these effects cannot be sufficiently obtained by adding 0, oi% without vortex, and on the contrary, these effects are impaired when the amount exceeds 1,0%. Therefore, the optimum range is 0, oi% to 1,0%. That is.

Next, regarding nickel, we refine the crystals to create cast materials.
And, it is effective for increasing the hardness of softened materials, and 0
．． If it is less than 0.01%, the effect cannot be expected at all, and
Since it has been found that melting and casting properties deteriorate when the content exceeds 1.0%, the desirable range is 0.01% to 1.0%.

In addition, titanium acts extremely effectively to further promote work hardenability and precipitation hardenability, and has a 0.
Addition of less than 0.01% has no practical effect; conversely, addition of less than 1.0%
It has been confirmed through experiments that if the amount exceeds 0.0%, the workability and even melting and casting properties will deteriorate.
The content is set at 1% to 1.0%.

Finally, germanium is extremely effective for work hardening at low processing rates, but it is also necessary to improve melting and casting properties, and if it is less than o, oi%, it will not have any noticeable effect. On the other hand, it has been confirmed that if the content exceeds 1.0%, a problem of suppressing crystal refinement occurs, and therefore the optimum range is set at 0.01% to 1.0%.

Next, Table 1 shows examples of the invention of this application along with known examples in terms of chemical components and component blending ratios by weight.

Table 1 In addition, the alloy of the above-mentioned known example is JISH2141 silver bullion 2
It is a seed.

Regarding the samples 1 to 7 of Examples in Table 1 above and the known samples, each material was melted using a high frequency heating melting furnace well known to those skilled in the art, and tlOxw50 XL15
After casting in the shape of 0ar, it is rolled to t5m with cold rolling rolls.
It was possible to roll it into a predetermined shape.

Next, each example sample and the known side sample obtained as described above were treated as follows to obtain a specimen for hardness measurement.

<Test piece for measuring hardness> (1) A test piece of a softened material obtained by holding a 15M rolled material in a predetermined shape in an electric furnace at 700°C for 60 minutes and then rapidly cooling it in water.

(2) A specimen of a 10% processed material obtained by rolling a softened material to 14.511IIn.

(3) 90 which rolled the softened material to t O, 5m
% processed material specimen.

<Hardness measurement method> Using a micro Vickers hardness tester, the hardness of the above specimen was measured under a load of 100 g and a load holding time of 30 seconds.

<Method for measuring the presence or absence of softening over time> Each sample specimen of 90% processed material was kept in a constant temperature room at 37° C. for 50 days, and changes in its hardness were examined.

The hardness measurement results are shown in Table 2 below.

As is clear from the hardness measurement results shown in Table 2 above, the high silver grade hard silver alloy of the invention of this application has significantly improved hardness compared to conventional alloys, and also softens over time. It can be seen that this has a good property of not causing any

<Effects of the Invention> As described above, according to the invention of this application, the hardness can be improved without losing the original excellent properties of silver, and the work-hardened material does not soften over time at all. However, despite the complicated composition ratio of the components, it has good melting and casting properties, making it extremely easy to use as a casting material. Therefore, the invention of this application is a high-grade hard silver alloy. It has an excellent effect that it can be used not only as an accessory, but also for industrial purposes such as electrical contacts.

Claims (2)

[Claims] (1) By weight, copper is 0.01% to 1.0%, nickel is 0.01% to 1.0%, and titanium is 0.01% to 1.0%.
, a titanium-containing high-silver-grade hard silver alloy comprising at least 97% silver and having work hardenability, precipitation hardenability, and melt castability. (2) By weight, copper is 0.01% to 1.0%, nickel is 0.01% to 1.0%, and titanium is 0.01% to 1.0%.
A titanium-containing high-silver-grade hard silver alloy comprising 0.01% to 1.0% germanium and 97% or more of the balance, and having work hardenability, precipitation hardenability, and melt castability.