Interfacial Microstructure Analysis of Oxide-Coated Ti Alloys and Prediction of Mechanical Properties as Composites

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05119
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 26030:Composite materials and interfaces-related
• Research Institution: University of Hyogo
• Principal Investigator: Miura Eri 兵庫県立大学, 工学研究科, 准教授 (70315258)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: チタン合金 / 酸化物 / 界面構造 / 複合材料 / 力学特性 / 有限要素法

Outline of Final Research Achievements

In the research and development of Ti alloys, which are being developed as substitutes for biological hard tissues, research and development in the areas of microstructure control and alloy design, as well as surface treatment technology, are being carried out respectively. In this proposal, we focus on Ti-Nb and Ti-Ta alloys that form compositionally continuous oxide films by self-oxidation, and investigate the micro- to nano-level microstructure of the oxide/alloy interface using metallographic and crystallographic methods, and material mechanics calculations that consider the oxide/alloy substrate as a continuum material. We investigate both interface structure control and structural and mechanical approaches from the viewpoints of interfacial microstructure control and structural and mechanical approaches. The oxidation mechanism of these alloys, and the contributions of the material and microstructure to the mechanical properties of Ti-based coating materials are elucidated.

Free Research Field

生体材料工学

Academic Significance and Societal Importance of the Research Achievements

本研究はバルク状態のTi酸化物の形成挙動や力学特性について調査した数少ない研究であると共に，表面処理を前提とした生体用金属材料の設計指針を示すものとして，工業的にも学術的にもユニークな研究である．本研究の成果として，酸化前のTiの合金化，特に共晶系酸化物を成す合金元素を選択することで，自己酸化皮膜の緻密化や高硬度化が可能であり，また基板金属と酸化物の界面構造の改変が可能である事，界面組織の傾斜化により界面剥離強度の向上が可能である事，連続構造体の材料力学計算により界面強度に最適な膜厚を比較的定量性よく解析可能であることを示した．耐熱構造材や電子材料としての可能性も広げるものと期待される．