Effect of geometrical distribution of sub-grain boundaries on creep properties of Ni-based superalloys

Research Project

Project/Area Number	24656411
Research Category	Grant-in-Aid for Challenging Exploratory Research
Allocation Type	Multi-year Fund
Research Field	Structural/Functional materials
Research Institution	Kobe University
Principal Investigator	TANAKA Katsushi 神戸大学, 大学院・工学研究科, 教授 (30236575)
Project Period (FY)	2012
Project Status	Completed (Fiscal Year 2012)
Budget Amount *help	¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000) Fiscal Year 2012: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000)
Keywords	超合金 / クリープ変形 / デンドライト境界 / 幾何的必要転位 / 引張圧縮非対称性
Research Abstract	Geometrically required dislocations are distributed at sub-grain boundaries that corresponds to interfaces of dendrites grown in Ni-based superalloys. In the present study, we have performed compressive creep tests to observe the development of creep dislocation networks at gamma/gamma-prime interfaces, and of parallel raft structure. When a compressive stress is applied along tothe growth direction, the magnitude of primary creep is very small compared with that applied perpendicular to the growth direction. We have constructed a creep testing machine that can use a very small specimen without dislocation networks in it.