Evaluation of impact strength and reliability of ceramic bearing ball for next-generation airplanes

Research Project

Project/Area Number	21560096
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Materials/Mechanics of materials
Research Institution	Ehime University
Principal Investigator	TAKAHASHI Manabu 愛媛大学, 大学院・理工学研究科, 教授 (20274334)
Co-Investigator(Renkei-kenkyūsha)	OGI Keiji 愛媛大学, 大学院・理工学研究科, 教授 (70281194) YASHIRO Shigeki 静岡大学, 大学院・工学研究科, 准教授 (00452681)
Project Period (FY)	2009 – 2011
Project Status	Completed (Fiscal Year 2011)
Budget Amount *help	¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000) Fiscal Year 2011: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000) Fiscal Year 2010: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000) Fiscal Year 2009: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
Keywords	破壊 / 衝撃 / 接触 / セラミック / リングクラック
Research Abstract	The equipments of pendulum impact test and weight-drop test were manufactured in order to evaluate the ring crack strength under impact load. In the pendulum impact test, a slanting collision is caused because alignment adjustment of balls center is difficult. The measurement is very difficult although collision load of ring crack initiation is theoretically computable. On the other hand, in weight-drop test, collision load of ring crack initiation is correctly measurable using a load cell. Equipment manufacture is also comparatively easy. The ring crack is attributed to binder destruction of the glassy phase between particles, impurities, etc. It is possible to investigate microscopic fracture from ring crack strength. In the collision contact, the strength of the ceramic ball rises and the scatter of them become small, because the crack length which participates in ring crack initiation is small compared with static contact.