Fabrication of functionally-graded beta titanium alloy as biomaterial by means of additive manufacturing

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K04070
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 18010:Mechanics of materials and materials-related
• Research Institution: Gifu University
• Principal Investigator: Uematsu Yoshihiko 岐阜大学, 工学部, 教授 (80273580)
• Co-Investigator(Kenkyū-buntansha): 柿内 利文 岐阜大学, 工学部, 准教授 (20452039)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 積層造形 / 複合構造 / チタン合金 / 強度特性

Outline of Final Research Achievements

A material with functionally-graded structure was created by 3D additive manufacturing. A hybrid structure was fabricated using maraging steel or Ti-6Al-4V alloy, which is a molten material, as a base material. Each powder was deposited on the base metal by selective laser melting (SLM). The dissimilar metal hybrid structure was also fabricated using Ti-6Al-4V powder deposited on beta-type titanium alloy, Gum-metal. The boundary between the molten material and the deposited part forms irregularities because the molten powder resolidifies on the substrate. But in the case of dissimilar metal hybrid structure, the substrate, Gum-metal, has a lower melting point than the Ti-6Al-4V alloy. Therefore, it was confirmed that the unevenness of the interface became severe. It was also clarified that the strength of the hybrid structure is mainly dominated by the strength of the deposited part.

Free Research Field

材料強度学

Academic Significance and Societal Importance of the Research Achievements

積層造形は複雑形状を比較的容易に作製できる手法として注目されているが，溶製材上に積層造形を施したいわゆるハイブリッド構造については研究が行われていなかった．本研究では，同種金属だけでなく，Ti-6Al-4V合金とベータ型チタン合金の組合せで異種金属ハイブリッド構造が作製可能である点を示した点は，工業的な意義が大きい．このような異種金属ハイブリッド構造は，基材と積層部で弾性係数が異なる傾斜構造となっており，医療用インプラントのような医療用構造としての実用化が期待できる．また，ハイブリッド構造の強度が積層部強度に主に支配されることを明らかにした点は，構造体の信頼性設計に応用することが可能である．