JPS5935670A - External parts for portable watch - Google Patents

Abstract

PURPOSE:To obtain parts for portable watches having excellent resistance to corrosion and abrasion by working an Ni-Cr alloy contg. respectively prescribed ratios of Ni, Cr and Al, Ti to a prototype, and subjecting the same simultaneously to an age hardening treatment and a plating diffusion treatment after plating in a high vacuum. CONSTITUTION:The case band for portable watches is worked to a prototype by using an Ni-Cr alloy of the compsn. contg., by weight, <=80% Ni, <=20% Cr, and 0.5-1.5% Al, Ti. The worked alloy is plated with Au in a 2-10mu thickness, and is then held for >=10hr at 500-700 deg.C in a high vacuum of, for example, 2-5X10<-5> Torr. An age hardening treatment and a plating diffusion treatment are applied simultaneously on said worked part by the above-mentioned holding, whereby the intended external part for portable watches is obtd. This external parts replace commonly used SUS materials and copper alloys, have high merchandise value, high quality and mass productivity and are inexpensive.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exterior part for a portable watch that has excellent corrosion resistance and wear resistance.

Conventional exterior parts for mobile watches include 5U83Q4.5U.
Stainless steel such as 8316T-+, brass coated with decorative plating, and carbide materials and partially precious metals are used for the scratch-resistant body.

However, although stainless steel has excellent corrosion resistance, it is hard
Since it is v200-350, it has the disadvantage that it is prone to scratches when used for a long time, and its original luster naturally disappears, reducing its commercial value. Copper alloys are often used because they are easy to process and have good plating properties. However, since the material strength is weak in local areas, it may become deformed or scratched due to external factors such as shocks when carried for a long period of time. In addition, the surface plating
It has the disadvantage that the copper alloy of the base material easily corrodes due to wear. Cemented carbide occupies one part of the product line as square-less cases, but it is expensive because it is powder molded, and it has the disadvantage of poor corrosion resistance because a binder is added to improve impact resistance. have.

The present invention eliminates these drawbacks and provides an unprecedented exterior component for a portable watch that has high commercial value and can replace stainless steel and copper alloy, which are the mainstream of exterior components for portable watches.

In other words, the present inventor has conducted various experiments using a material that has age hardening ability, since it has corrosion resistance comparable to stainless steel and is hard to scratch if hardened to Hυ400 or more in long-term use. We have completed the present invention by discovering that an alloy containing 150% N front edge satisfies the above conditions and that decorative gold plating diffuses under the same conditions as age hardening treatment. Examples will be given below and specifically explained in detail.

Example-1 Ni with a weight ratio of 8096 or less and O with 120% or less
r, and N? with a composition containing 0.5% to 1.5% Al1-, Ti? After processing the body of a mobile watch to its original shape using a Cr-based alloy, gold plating was applied in the range of 2 to 10μ, and then age hardening treatment and plating diffusion treatment were performed under the following conditions to prepare the sample. Completed.

Processing conditions Temperature: 600°C Holding time: 15 to 35 hours Atmosphere: 2 to 5 X Hl-5 Torr Cooling method: Slow cooling Table 1 shows the results of corrosion resistance tests of samples of the present invention and conventionally used shells. be.

Note that the sample used for comparison with the present invention was prepared by a conventional method.

Table 1: ◎Excellent ○Good △Slightly inferior ×Poor Surface corrosion test results are determined comprehensively by performing artificial sweat resistance tests, seawater resistance tests, and salt spray tests, which are required for exterior parts of mobile watches. This was determined based on the following.

All of the conventionally used shell materials had poor corrosion resistance, and even 5U8316L, which had the best corrosion resistance, caused slight discoloration. The samples of the present invention performed very well regardless of whether they were plated or not, and no corrosion occurred even in a one-year portable test conducted separately.

Table 2 shows a comparison of the hardness of a sample of the present invention and a conventionally used cylinder, as well as the comparison results of a wear resistance test.

Table 2 ◎ Excellent ○ Slightly inferior gloss △ Lack of gloss and scratches 〈 × Inferior In the comparative test in Table 1, the product of the present invention (even without RI plating, the corrosion resistance was very excellent, so it was not used conventionally) The silk raw material and the age-hardened raw material of the present invention were polished to a mirror finish, the cylinder was completed, a mobile test was conducted, and the abrasion resistance was compared.Three years after the mobile test, all of the conventional products showed no change in luster. Even in the SUE month, which had the best appearance, the gloss was poor due to countless minute scratches, whereas the product of the present invention had no change in gloss at all and was very excellent.

In the present invention, the composition range is limited because of workability, corrosion resistance,
and age hardenability properties.

It should be noted that the above-mentioned embodiments constitute a part of the present invention, and it can be readily agreed that similar effects can be obtained with bands and buckles outside the body plate.

As described in detail above, according to the present invention, it has excellent corrosion resistance, hardens to around Hυ500 even though it hardens through age hardening treatment, and is difficult to cause scratches.Also, it is possible to perform the diffusion treatment of decorative plating at the same time, so it is suitable for use in mobile watches. 5t is the mainstream for exterior parts
It is possible to provide an economically inexpensive exterior part for a mobile watch that has high commercial value, high quality, excellent mass production, and is an alternative to JS materials and copper alloys.

that's all Applicant: Daini Seikosha Co., Ltd. Agent Patent Attorney Mogami

Claims (1)

[Claims] In both cases, the weight ratio of Ni is 80% or less, Ni is 20% or less (7
J) Cr and 0.5% to 1.5 q6. AA,
A cell phone characterized in that an N6-Cr alloy containing Tz is processed to its original shape, and after being plated, it is held in a high vacuum at a temperature of 500 to 700°C for 10 hours or more to undergo age hardening treatment and plating diffusion treatment at the same time. Exterior parts for watches.