【発明の詳細な説明】[Detailed description of the invention]
本発明は指輪、ネツクレス、ブローチ、ネクタ
イピン、カフスボタン、時計枠、時計バンド、ラ
イター、筆記用具、眼鏡枠、イヤリング等の材料
として使用する白金合金の製造方法に関するもの
である。
従来、上述の如き装飾品材料としては白金−パ
ラジウム（５〜15w／ｏ）系合金が多用されてい
る。
この合金は、加工性、鋳造性に優れているが、
機械的強さ特に硬さが低い為、研摩中にすり傷、
押傷が付き易く且つ光沢が出にくく、また完成品
として使用している場合も傷が付き易く、また宝
石付指輪の場合、宝石を止めている部分がゆるん
で宝石が脱落するという欠点があつた。
本発明は上記の欠点を解消せんが為になされた
ものであり、機械的強さ、加工性に優れた装飾品
用白金合金の製造方法を提供せんとするものであ
る。
本発明による装飾品用白金合金の製造方法は、
すず２〜10重量％及び残部白金よりなる合金を溶
体化処理後時効処理を施し、当該合金の硬度を高
くすることを特徴とするものである。
本発明による装飾品用白金合金の製造方法に於
いて、すずを添加した理由は、Pt−Snの２元状
態図からも明らかなようにSnはPtに対して1365
℃で最大固溶量8w／ｏを示し、その固溶度は温
度下降と共に漸次減少し、固溶体領域まで加熱し
急冷する溶体化処理を行つた後、適当な温度で時
効させると著しい時効硬化性を現わす為である。
その添加量が2w／ｏ未満では硬さの改善が殆ん
どなく、10w／ｏを超えるとPtとSnの金属間化
合物の量が多くなり、加工性が悪くなるからであ
る。
以下、本発明による装飾品用白金合金の製造方
法の効果を明瞭ならしめる為に実施例及び従来例
について述べる。
第１表に示す成分組成の実施例No.１〜No.４の装
飾品用白金合金と従来例No.５、No.６の装飾品用白
金合金の溶体化処理後の硬度、時効後の硬度、耐
汗性について測定したところ、第２表のような結
果を得た。
The present invention relates to a method for producing a platinum alloy used as a material for rings, necklaces, brooches, tie pins, cufflinks, watch frames, watch bands, lighters, writing utensils, eyeglass frames, earrings, and the like. Conventionally, platinum-palladium (5 to 15 w/o) alloys have been widely used as materials for decorative items such as those mentioned above. This alloy has excellent workability and castability, but
Due to low mechanical strength, especially hardness, scratches and scratches occur during polishing.
It is easy to get scratched and hard to get shiny, and it is also easy to get 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 can fall off. Ta. The present invention was made in order to eliminate the above-mentioned drawbacks, and it is an object of the present invention to provide a method for producing a platinum alloy for decorative articles that has excellent mechanical strength and workability. The method for producing a platinum alloy for ornaments according to the present invention includes:
It is characterized in that an alloy consisting of 2 to 10% by weight of tin and the balance platinum is subjected to solution treatment and then aging treatment to increase the hardness of the alloy. The reason why tin is added in the method of manufacturing platinum alloy for ornaments according to the present invention is that, as is clear from the binary phase diagram of Pt-Sn, Sn is 1365% higher than Pt.
It shows a maximum solid solution amount of 8 w/o at °C, and the solid solubility gradually decreases as the temperature decreases, and after performing solution treatment that heats to the solid solution region and rapidly cools it, it exhibits remarkable age hardening when aged at an appropriate temperature. This is to express the
If the amount added is less than 2 w/o, there is little improvement in hardness, and if it exceeds 10 w/o, the amount of intermetallic compounds of Pt and Sn increases, resulting in poor workability. Examples and conventional examples will be described below in order to clarify the effects of the method for manufacturing a platinum alloy for decorative articles according to the present invention. Hardness after solution treatment of platinum alloys for ornaments of Examples No. 1 to No. 4 and platinum alloys for ornaments of Conventional Examples No. 5 and No. 6 with the composition shown in Table 1, after aging When the hardness and sweat resistance were measured, the results shown in Table 2 were obtained.
【表】【table】
【表】
なお人工汗試験はNH4Cl15.5ｇ／、NaCl20
ｇ／、酢酸2.5ｇ／、尿素５ｇ／、乳酸15
ｇ／、PH4.7の液組成で液温40℃、240時間浸漬
後判定した。
また、第１表の実施例No.２について1200℃で溶
体化処理後、600℃、700℃の温度で時効処理を施
し、その硬度と時効時間の関係を測定したとこ
ろ、図に示す如く時効処理によつて顕著な硬度上
昇を示す結果を得た。
上記で明らかなように本発明による装飾品用白
金合金は、単に溶体化処理だけした合金や従来の
装飾品用白金合金に比し時効処理後の硬さが著し
く優れ、耐汗性についても優れていることが判
る。
以上詳記した通り、本発明の製造方法による装
飾品用白金合金は加工性、機械的強さ、耐汗性が
極めて優れているので、従来の装飾品用白金合金
にとつて代わることのできる画期的なものと言え
る。[Table] The artificial sweat test was performed using NH 4 Cl15.5g/, NaCl20
g/, acetic acid 2.5 g/, urea 5 g/, lactic acid 15
Judgment was made after immersion for 240 hours at a liquid temperature of 40°C with a liquid composition of 1.2 g/g/, pH 4.7. In addition, for Example No. 2 in Table 1, after solution treatment at 1200°C, aging treatment was performed at temperatures of 600°C and 700°C, and the relationship between hardness and aging time was measured. The results showed that the treatment significantly increased the hardness. As is clear from the above, the platinum alloy for ornaments according to the present invention has significantly superior hardness after aging treatment and superior sweat resistance compared to alloys that have been simply solution-treated or conventional platinum alloys for ornaments. It can be seen that As detailed above, the platinum alloy for ornaments produced by the production method of the present invention has extremely excellent workability, mechanical strength, and sweat resistance, and can therefore replace conventional platinum alloys for ornaments. It can be said to be groundbreaking.
【図面の簡単な説明】[Brief explanation of drawings]
図は、実施例No.２を600℃及び700℃で時効処理
したときの時効時間と硬度の関係を示すグラフで
ある。
The figure is a graph showing the relationship between aging time and hardness when Example No. 2 was aged at 600°C and 700°C.