Development of dental prosthesis made of semi-precious materials with specific hardening mechanism

2018 Fiscal Year Final Research Report

• Project/Area Number: 16H04520
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Structural/Functional materials
• Research Institution: Meijo University
• Principal Investigator: Toshikazu Akahori 名城大学, 理工学部, 准教授 (00324492)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: デンタルマテリアル / 銀合金 / ミクロ組織 / 力学的特性

Outline of Final Research Achievements

G12 subjected to ST at relatively high temperature of 1173 K was composed of three kinds of phases with Ag-rich α2 phase, Cu-rich α1 phase and β phase of Pd-Cu intermetallic compound. Although nominal melting point of G12 was around 1233 K, the high Cu concentration area like α1 phase was partially dissolved and then the α1, α2 and partial β phases re-precipitated during cooling. On the other hand, the microstructure of G12 aged at 673 K after ST at 1023 K (STA) was mainly composed of two kinds of phases with α2 and α1 phases with a small amount of β phase, which was a typical microstructure of STA. The Vickers hardness of G12 subjected to ST at 1173 K was identical to that of the same alloy subjected to STA although the tensile strength, fatigue limit and ductility deteriorated to some degrees.

Free Research Field

歯科材料

Academic Significance and Societal Importance of the Research Achievements

本合金の異常な強化機構を明らかにすることにより、現在行われている複雑な加工熱処理の代わりに高力学的機能化プロセスを大幅に簡略化することができ、製造コストの削減が可能と考えている。また、本研究成果は、現在、応用時の破損および耐食性が大きく問題視されている歯科補綴物の使用に対する信頼性を飛躍的に向上させることが可能となる。
本合金における簡易熱処理によるユニークな強化機構を解明することにより、微細組織制御の新規な展開が期待でき、歯科理工学分野の更なる展開を図ることができると考えている。