JP2011225902A

JP2011225902A - Gold alloy for casting

Info

Publication number: JP2011225902A
Application number: JP2010094091A
Authority: JP
Inventors: Yasusuke Imai; 庸介今井; Yoshinori Doi; 義規土井
Original assignee: Ishifuku Metal Industry Co Ltd
Current assignee: Ishifuku Metal Industry Co Ltd
Priority date: 2010-04-15
Filing date: 2010-04-15
Publication date: 2011-11-10

Abstract

PROBLEM TO BE SOLVED: To provide a gold alloy for casting excellent in mechanical property while showing rich golden color tone.SOLUTION: This gold alloy for casting is characterized by comprising by mass% 70-75% Au, 6-13% Ag, 0.1-1% Pt, 11-15% Cu, 0.05-0.2% Ir, Ru, Rh and/or Re and 0.2-2% Zn.

Description

本発明は、鋳造用金合金に関するものである。 The present invention relates to a gold alloy for casting.

歯科治療において修復物作製に用いられる鋳造用金合金は、精密鋳造によって所望の形状を与えることができ、適合性に優れる。また、熱処理によって機械的性質を適度に調整できるため、用途はインレー，クラウン，ブリッジ，デンチャーなど多岐にわたる。
歯科に用いる鋳造用金合金の成分は、Auをベースとして、Ag、Pt、Pd及びCuのほか、種々の微量添加元素により構成されるが、その用途によって要求される機械的性質が異なるため、熱処理による軟化，硬化特性を勘案して組成設計する。鋳造用金合金の色調は、Auに上記のような元素を添加するため本来の金の色調が薄まってしまう。従って、高い機械的性質と豊かな金色を両立させることが難しい。なかでも、PtやPd等の白金族元素の添加は、色調を著しく淡黄色化してしまう。
特許文献１には、60〜90重量％のAu、0〜20重量％のAg、0〜7重量％のPd、0〜11重量％のPt、0〜20重量％のCu、0〜2重量％のZn、0〜1重量％のSn及び0〜3重量％のInならびに微量の結晶粒リファイナから成る歯科鋳造用金合金が開示されている。しかし、当該発明の合金は、Pt及びPdが高含有であるため、鋳造用金合金としての色調は淡く、濃い金色の金合金を提供することは困難である。 A casting gold alloy used for restoration preparation in dental treatment can give a desired shape by precision casting and has excellent compatibility. In addition, since the mechanical properties can be appropriately adjusted by heat treatment, the applications are diverse, such as inlays, crowns, bridges, and dentures.
The component of the gold alloy for casting used for dentistry is composed of various trace additive elements in addition to Ag, Pt, Pd and Cu, based on Au, but the mechanical properties required by the application differ, The composition is designed in consideration of the softening and hardening characteristics due to heat treatment. As for the color tone of the gold alloy for casting, since the above-described elements are added to Au, the original color tone of gold is diluted. Therefore, it is difficult to achieve both high mechanical properties and rich gold color. In particular, the addition of platinum group elements such as Pt and Pd causes the color tone to become extremely pale yellow.
Patent Document 1 includes 60 to 90% by weight of Au, 0 to 20% by weight of Ag, 0 to 7% by weight of Pd, 0 to 11% by weight of Pt, 0 to 20% by weight of Cu, and 0 to 2% by weight. A dental casting gold alloy is disclosed comprising 1% Zn, 0-1 wt% Sn and 0-3 wt% In and a minor amount of grain refiner. However, since the alloy of the present invention has a high content of Pt and Pd, the color tone as a gold alloy for casting is light, and it is difficult to provide a dark gold alloy.

特開平１１−１５２５３１号公報JP 11-152531 A

本発明の目的は、豊かな金色を呈しながら、機械的性質の優れた鋳造用金合金を提供することにある。 An object of the present invention is to provide a gold alloy for casting excellent in mechanical properties while exhibiting a rich gold color.

Au：70〜75mass%、Ag：6〜13mass%、Pt：0.1〜1ｍass%、Cu：11〜15mass%、Ir、Ru、Rh及び／又はRe：0.05〜0.2mass%、Zn：0.2〜2mass%からなることを特長とする鋳造用金合金。 Au: 70-75 mass%, Ag: 6-13 mass%, Pt: 0.1-1 mass%, Cu: 11-15 mass%, Ir, Ru, Rh and / or Re: 0.05-0.2 mass%, Zn: 0.2-2 mass% A gold alloy for casting characterized by comprising

本発明によれば、豊かな金色調を呈しながら、機械的性質の優れた金合金を提供できる。 According to the present invention, it is possible to provide a gold alloy having excellent mechanical properties while exhibiting a rich gold color tone.

（金合金の作製）
本発明の実施例及び比較例の組成を表１に示す。
各金属を秤量し、アーク溶解炉にて溶製し、厚さ1mmまで圧延し裁断して、実施例及び比較例の鋳造用金合金を得た。なお、圧延の途中で大気中、700℃，2hの条件で、熱処理した。 (Production of gold alloy)
Table 1 shows the compositions of Examples and Comparative Examples of the present invention.
Each metal was weighed, melted in an arc melting furnace, rolled to a thickness of 1 mm and cut to obtain gold alloys for casting of Examples and Comparative Examples. In the middle of rolling, heat treatment was performed in air at 700 ° C. for 2 hours.

（試験片の作製）
色調評価用試験片は、長さ15×15mm、厚さ1.2mmのワックスパターンを作製し、クリストバライト系埋没材で埋没・焼成した後，真空加圧式鋳造機を用いて鋳造した。次に、鋳造体から埋没材を除去して、スプルーを切断して、片面を鏡面になるまで研磨して仕上げた。 (Preparation of test piece)
The test piece for color tone evaluation was prepared by preparing a wax pattern having a length of 15 × 15 mm and a thickness of 1.2 mm, burying and firing with a cristobalite investment material, and then casting using a vacuum pressure casting machine. Next, the investment was removed from the casting, the sprue was cut, and one side was polished to a mirror surface and finished.

耐力評価用の引張試験片は、前記と同様の鋳造方法で直径2ｍｍ，長さ50mmの丸棒を鋳造し、軟化熱処理として、650℃で10分間、大気中で熱処理した。次に、硬化熱処理として300℃で15分間、大気中で熱処理した。 Tensile test pieces for proof stress evaluation were casted as a round bar having a diameter of 2 mm and a length of 50 mm by the same casting method as described above, and heat-treated in the atmosphere at 650 ° C. for 10 minutes as a softening heat treatment. Next, heat treatment was performed in the air at 300 ° C. for 15 minutes as a curing heat treatment.

（色調の評価）
実施例及び比較例の金合金の色調は、純金との色差ΔE^＊によって評価した。
色差ΔE^＊は、CIELab表色系において、２色間の明度L^＊、彩度a^＊及び彩度b^＊の差（ΔL^＊、Δa^＊及びΔb^＊）の２乗和の平方根で定義される値で、肉眼では判定しづらい色調の差を定量的に表す指標である。色差ΔE^＊が大きいほど、２色間の隔たりが大きく、色調が異なることを表す。
純金鏡面と前記方法で作製した試験片鏡面とのΔL^＊、Δa^＊及びΔb^＊を色差計（ビックガードナー社、カラーガイド）で計測し、色差ΔE^＊を求めた。
結果を表１に示す。 (Evaluation of color tone)
The color tone of the gold alloys of Examples and Comparative Examples was evaluated by the color difference ΔE ^{* from the} pure gold.
The color difference ΔE ^* is defined as the square root of the sum of squares of the difference between the lightness L ^* , saturation a ^*, and saturation b ^* (ΔL ^* , Δa ^*, and Δb ^* ) between the two colors in the CIELab color system. This is an index that quantitatively represents a difference in color tone that is difficult to determine with the naked eye. The larger the color difference ΔE ^* , the greater the separation between the two colors, indicating that the color tone is different.
ΔL ^* , Δa ^*, and Δb ^* between the pure gold mirror surface and the mirror surface of the test piece prepared by the above method were measured with a color difference meter (Big Gardner Co., Color Guide) to obtain a color difference ΔE ^* .
The results are shown in Table 1.

（耐力の評価）
引張試験片の0.2％耐力を、引張試験機を用いて測定した。
結果を表１に示す。 (Evaluation of yield strength)
The 0.2% proof stress of the tensile test piece was measured using a tensile tester.
The results are shown in Table 1.

（結果）
比較例の金合金の色差ΔE^＊がおよそ18〜23の金色であったのに対し、実施例の金合金の色差ΔE^＊は18未満の金色であった。従って、本発明に係る金合金は、純金との色差が小さく、従来品に比して豊かな金色調を呈することが確認された。 (result)
The color difference ΔE ^* of the gold alloy of the comparative example was about 18 to 23, whereas the color difference ΔE ^* of the gold alloy of the example was less than 18. Therefore, it was confirmed that the gold alloy according to the present invention has a small color difference from pure gold and exhibits a rich gold color tone as compared with a conventional product.

また、比較例の金合金の耐力が515〜675MPaであったのに対し、実施例の金合金の耐力は552〜639MPaであった。従って、本発明に係る金合金は、従来品に比して劣らず、優れた機械的強度を有することが確認された。 Moreover, the proof stress of the gold alloy of the comparative example was 515 to 675 MPa, whereas the proof stress of the gold alloy of the example was 552 to 639 MPa. Therefore, it was confirmed that the gold alloy according to the present invention has excellent mechanical strength as compared with the conventional products.

従って、本発明に係る金合金によれば、高い機械的性質と豊かな金色を両立させることができる。 Therefore, according to the gold alloy according to the present invention, it is possible to achieve both high mechanical properties and a rich gold color.

Claims

Au: 70-75 mass%, Ag: 6-13 mass%, Pt: 0.1-1 mass%, Cu: 11-15 mass%, Ir, Ru, Rh and / or Re: 0.05-0.2 mass%, Zn: 0.2-2 mass% A gold alloy for casting characterized by comprising