JP2968314B2 - High silver grade hard silver alloy containing titanium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The disclosed technology belongs to the field of silver alloy composition technology.

<Summary of the Invention> The invention of this application relates to a hard silver alloy having a high silver quality. In particular, the weight ratio is 0.01% to 1.0% for copper, 0.01% to 1.0% for nickel, 0.01% to 1.0% for titanium, The present invention further relates to a titanium-containing high silver grade hard silver alloy having a composition of 0.01% to 1.0% of germanium and 97% or more of residual silver.

<Conventional Technology> As is well known, silver is used in money, various silverware, and accessories because of its excellent color tone, which is a so-called silvery white color, and good workability when commercialized. Widely used.

Therefore, in terms of its physical characteristics, such as low electrical resistance, high thermal conductivity, and excellent chemical resistance, such as excellent oxidation resistance, it is useful in industrial fields such as electrical contacts. It is also often used purposely.

In particular, coins, silverware, accessories, and the like are made by a so-called lost wax method or machining means, and a high silver grade silver alloy is widely used as a material thereof.

<Problems to be Solved by the Invention> However, the high silver grade silver alloy of the seed conventional mode is not only poor in work hardenability due to extremely low hardness, but also easily softens over time, and furthermore, the crystal is It is coarse and has drawbacks such as damage during processing and wear from micro scratches during use of the product.

<Object of the Invention> The purpose of the invention of this application is based on the above-mentioned conventional technology, and is a technical problem to solve the problem of a high silver grade silver alloy as a raw material. Softening does not occur over time, and furthermore, it has good melting and casting properties and can be widely used not only for accessories such as accessories, but also industrially, which is an advantage in the processing technology application field in the metal products industry. It is intended to provide a titanium-containing high silver grade hard silver alloy.

<Means and Actions for Solving the Problems> In order to solve the above-mentioned problems, the constitution of the invention of the present application having the above-mentioned claims in accordance with the above-mentioned objects has been described in terms of weight ratio of each of copper, nickel and titanium. The weight ratio is 0.01
% To 1.0%, and germanium in a weight ratio of 0.01% to 1.0%
It is a high silver grade hard silver alloy with 97% or more of residual silver, can be performed well by the lost wax method and machining means, has good work hardenability and precipitation hardenability, has excellent melt castability, and has a fine crystal. In addition, technical measures were taken to prevent softening over time and to prevent wear and the like during use of the final product.

<Principle Background of the Invention> The reasons for limiting the weight blending ratio of each additive element in the constitution of the above-mentioned claims will be explained qualitatively and quantitatively based on experiments.

First, for copper, crystal coarsening is prevented.
Not only is it necessary to maintain the function of increasing the hardness by precipitation hardening, but it is also necessary for the function of improving work hardenability. If the addition is less than 0.01%, these functions cannot be obtained sufficiently. It has been confirmed that these functions are impaired in the above cases. Therefore, the range of 0.01% to 1.0% is set to the range of the optimum weight mixing ratio.

Next, as for nickel, it is effective to refine the crystal to increase the hardness of the cast material and the softening material, and if less than 0.01%, the effect is hardly expected,
Further, since it has been found that when the content is more than 1.0%, the melt castability is deteriorated, the range of 0.01% to 1.0% is set to a desirable range of the weight ratio.

Titanium acts very effectively to further promote work hardening and precipitation hardening.
It has been confirmed by experiments that the addition of less than 01% has no practical effect, and that the addition of more than 1.0% results in inferior workability and furthermore, poor melting and castability. % To 1.0%.

Lastly, germanium is not only extremely effective for work hardening at low processing rates, but is also necessary for improving melt castability. When the proportion of germanium is less than 0.01%, There is no effect to see, conversely 1.
When the content exceeds 0%, it is confirmed that a problem of suppressing the crystal refinement occurs, and therefore, the range of the optimal weight mixing ratio is determined.
It is 0.01% to 1.0%.

Next, the examples of the invention of this application are shown in Table 1 by showing the chemical components and component mixing ratios in combination with known examples by weight ratio.

Incidentally, the alloy of the above-mentioned known example is silver metal according to JISH 2141.

Each of the first to seventh samples of the example in Table 1 and the eighth sample
For known examples of the sample, each material was melted using a high-frequency heating melting furnace well known to those skilled in the art, t10 × w50 × L150mm
After casting in the shape of, rolled into a predetermined shape of t5mm with a cold rolling roll, then, each of the example samples obtained as described above,
A sample of the known example was processed as follows to obtain a test piece for hardness measurement, and the hardness was measured.

<Specimen for hardness measurement> (1) Rolled material having a predetermined shape of t5mm was placed in an electric furnace at 700 ° C for 60 hours.
Specimen of softened material quenched in water after holding for a minute.

(2) A sample of a 10% processed material obtained by rolling a softened material to t4.5 mm.

(3) A sample of a 90% processed material obtained by rolling a softened material to t0.5 mm.

<Hardness Measurement Method> The hardness of each of the above-described specimens was measured using a micro Vickers hardness meter at a load of 100 g and a load holding time of 30 seconds.

<Measurement Method of Presence or Absence of Temporal Softening> Each of the sample specimens (1), (2) and (3) was kept in a thermostatic chamber at 37 ° C. for 50 days, and the change in hardness was examined.

 The results of hardness measurement 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 as compared with the conventional alloy, and has a softening with time. It can be seen that the film has a good property that it does not occur.

<Effects of the Invention> As described above, according to the invention of this application, the hardness can be improved without losing the inherently excellent properties of the high silver grade hard silver alloy, and the work-hardened material is completely time-dependent. Not only does it not soften, but despite its complex composition ratio, it has good melt casting properties and good work hardening and extrusion hardening properties, making it extremely easy to use as a casting material. The crystal refinement is promoted to prevent damage during processing and wear during use. Therefore, the invention of this application is not limited to the use of high silver grade hard silver alloy as money, silverware, and accessories, There is an excellent effect that industrial use of electrical contacts and the like can be made significant.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) C22C 5/06-5/10

Claims (1)

(57) [Claims] (1) A silver composition comprising 0.01% to 1.0% of copper, 0.01% to 1.0% of nickel, 0.01% to 1.0% of titanium, 0.01% to 1.0% of germanium, and 97% or more of the balance by weight. Titanium-containing high silver grade hard silver alloy having good work hardenability, precipitation hardenability, and melt castability, and being added to crystal refinement so as to prevent softening with time.