| Project/Area Number |
06452148
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Materials/Mechanics of materials
|
|---|
| Research Institution | KYOTO UNIVERSITY |
|---|
Principal Investigator |
KOMAI Kenjiro Kyoto Univ., Graduate School of Engineering, Professor, 工学研究科, 教授 (70025948)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
SHIROSHITA Sohei Kyoto Univ., Graduate School of Engineering, Assistant, 工学研究科, 助手 (80026252)
MINOSHIMA Kohji Kyoto Univ., Graduate School of Engineering, Associate Prof., 工学研究科, 助教授 (50174107)
|
|---|
| Project Period (FY) |
1994 – 1995
|
| Project Status |
Completed (Fiscal Year 1995)
|
| Budget Amount *help |
¥7,400,000 (Direct Cost: ¥7,400,000)
Fiscal Year 1995: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1994: ¥6,400,000 (Direct Cost: ¥6,400,000)
|
|---|
| Keywords | High-Strength and High Modulus Fiber / Ceramic Fiber / Aramid Fiber / Fracture / Single Fiber Test / Environmental Strength Atomic Force Microscope / Atomic Force Microscope / 原子間力顕微鏡 / 複合材料強化繊維 |
|---|
| Research Abstract |
High-strength and high-elastic modulus fibers are gaining increasing demand for further technological areas. This investigation demonstrates the fracture behavior of single fiber including environmental influences of water, vacuum, electron radiation, and ultra-violet radiation. Fiber damage was closely examined by using high-resolution scanning electron microscope and atomic force microscope. The fibers investigated were ceramic precursor fiber including alumina (Altex by Sumitomo) , SiC (Nicalon by Nippon Carbon) and Si-C-Ti-O (Tyranno by Ube) , and organic fibers, aramid fibers of Kevlar by Du Pont and Technora by Teijin.
The single ceramic fiber strength decreased with increasing water content in an environment and with decreasing displacement rate. Nanoscopic evaluation of single fiber surface by AFM showed that water molecule induced slow crack growth, resulting in a decrease in fiber strength. As for aramid fibers, the longitudinal tensile strength and longitudinal and transverse elastic modulus decreased by water absorption and ultraviolet radiation. However, a decrease of mechanical properties by electron radiation was small. The longitudinal tensile strength also decreased in vacuum, and its decrease was promoted by changing an environment from vacuum to air. Nanoscopic evaluation by using AFM showed that surface damage including "nodule" and "graves" was promoted by water absorption, ultraviolet radiation and vacuum environment, and it promoted fiber splitting, resulting in mechanical properties of aramid fibers.
|
