Fabrication of high strength and high ductility titanium via high pressure gas jet milling and its deformation mechanism.

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K18248
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Material processing/Microstructural control engineering
• Research Institution: Ritsumeikan University
• Principal Investigator: Ota Mie 立命館大学, 理工学部, 助教 (30710587)
• Co-Investigator(Renkei-kenkyūsha): AMEYAMA Kei 立命館大学, 理工学部, 教授 (10184243)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: 組織制御 / 高強度高延性 / 超強加工 / 粉末冶金

Outline of Final Research Achievements

The harmonic structure was successfully created by controlled milling of fine-sized pure Ti powder via jet milling followed by spark plasma sintering. Spark plasma sintering of milled powder resulted in the formation of a “harmonic” structure wherein the severely deformed shell regions of the milled powders transformed to a three dimensional network of equiaxed fine-sized grains, enclosing the coarse-grained “core” areas. The pure Ti compacts with a harmonic structure exhibited a significant enhancement in the strength without compromising the ductility. The improved mechanical properties of the harmonic structure compacts were attributed to the specific topological distribution of high strength fine-grained “shell” and ductile coarse-grained “core” regions; as such a microstructure promotes uniform distribution of strain during plastic deformation and avoids the localized plastic deformation in the early stages of deformation.

Free Research Field

材料工学