JPS59150039A - Platinum alloy for accessory - Google Patents

Abstract

PURPOSE:To obtain a Pt alloy for accessories with superior mechanical strength and castability as well as superior workability by adding specified amounts of Co and Cu to Pt as a principal component. CONSTITUTION:The composition of a Pt alloy used as a material for a ring, a necklace, a brooch, a tiepin, cuff links, etc. is composed of 84-96wt% Pt, 1- 10wt% Co and the balance Cu. The reason for the addition of Co is that Co improves the mechanical strength and castability while satisfying the requirements that the reaction with a casting mold must be inhibited during casting and that the concn. of oxygen can be controlled during casting. When the Co content exceeds 10wt%, the workability is remarkably deteriorated. The reason for the addition of Cu is that Cu further improves the mechanical strength by hardening.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a pilgrimage ring, a spear necklace, a frock, a tie pin, a cufflink, and a watch hunt with two watch frames.

This invention relates to the improvement of platinum alloys used as materials for lighters, writing utensils, eyeglass frames, earlinks, etc.

Conventionally, platinum-palladium (5-15% by weight) alloys have been widely used as materials for the above-mentioned decorative items, and platinum-palladium-copper alloys have also been used.

However, although the former platinum-palladium (5-15% by weight) alloy has excellent workability and castability, it has low mechanical strength, particularly low hardness, and is easily scratched and pressed during polishing. It is difficult to produce luster and is easily scratched when used as a finished product, and in the case of rings with jewels, the part that holds the jewels loosens and the jewels fall off.

Also, the latter platinum-palladium-copper alloy has excellent workability G like the platinum-palladium alloy, and also has excellent mechanical properties, and because it reacts with the mold during casting, fine patterns do not appear. The problem was that it became unclear, and that cavities were formed because the oxygen concentration was not suppressed.

The present invention has been made in order to overcome the above-mentioned drawbacks, and aims to provide a platinum alloy for ornaments that is excellent in not only workability but also mechanical strength and castability.

The platinum alloy for ornaments according to the present invention consists of 84 to 96% by weight of platinum, 1 to 10% by weight of cobalt, and the balance copper.

The reason why cobalt is added to the platinum alloy for ornaments according to the present invention is that it satisfies the conditions of not reacting with the mold during casting, suppressing oxygen concentration during casting, and improving mechanical strength and castability. This is because the amount added is 1~
The reason why it is set at 10% by weight is that if it is less than 1% by weight, improvements in mechanical strength and castability will be low, and if it exceeds 10% by weight, workability will be significantly reduced.

The reason why copper is added is to harden and further improve mechanical strength.

Examples and conventional examples will be described below in order to clarify the effects of the platinum alloy for ornaments according to the present invention.

The hardness of the platinum alloys for ornaments of Examples 1 to 3 and the platinum alloys for ornaments of conventional examples 4 and 5 shown in the left column of the table below. The degree of occurrence was measured after annealing, and the results shown in the right column of the table below were obtained.

(Left below) As is clear from the table above, the platinum alloy for ornaments according to the present invention has superior hardness after annealing compared to conventional platinum alloys for ornaments, and reproduces the fine patterns of the mold when cast. It can be seen that the quality is also extremely good.

As detailed above, the platinum alloy for ornaments of the present invention has extremely excellent workability, mechanical strength, and castability, so it can be said to be an epoch-making product that can replace conventional platinum alloys for ornaments. .

Applicant: Tanaka Kikinzoku Kogyo Co., Ltd.

Claims (1)

[Claims] A platinum alloy for ornaments consisting of 84 to 96% by weight of platinum, 1 to 10% by weight of cobalt, and the balance copper.