1993 Fiscal Year Final Research Report Summary
ON THE CORROSION AND STATIC FATIGUE CHARACTERISTICS OF BIO-CERAMICS
| Project/Area Number |
05452128
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Materials/Mechanics of materials
|
|---|
| Research Institution | Kogakuin University |
|---|
Principal Investigator |
KIMURA Yuji KOGAKUIN UNIVERSITY FACULTY OF ENGNG.PROFESSOR, 工学部, 教授 (90107160)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
YAKO Takao YOKOHAMA NATIONAL UNIV.ASSOCIATE FACULTY OF EDUCATION,PROFESSOR, 教育学部, 助教授 (40111637)
FUJIWARA Yukio FACULTY OF ENGNG.LECTURER, 工学部, 講師 (80100361)
|
|---|
| Project Period (FY) |
1993 – 1994
|
| Keywords | Corrosion / static fatigue / bio-ceramics / Iactic Ringer's solution / grain boundary / Iow index planes / fracture toughness / bending strength |
|---|
| Research Abstract |
Corrosion and static fatigue characteristics of bio-ceramics, that is, polycrystalline alumina and single crystal sapphire in isotonic sodium chloride solution and lactic Ringer's solution werre investigated. Also, bending strength and fracture toghness were evaluated.
The results obtained are summarized as follows :
1.Single crystal sapphire has superior strength characteristics comparing to polycrystalline alumina. However, sapphire shows inferior fracture toughness.
2.Single crystal sapphire also has superior corrosion characteristics comparing to polycrystalline alumina. Some facet corrosion and a few corrosion pits were recognized on single crystal sapphire. On the other hand, more intense corrosions were recognized on polycrystalline alumina.
3.It may imply that, for strength and corrosion behaviors, grain boundary plays an important role as the defects and the corrosion site of these materials.
4.Polycrystalline alumina have superior static fatigue sharacteristics comparing to that of glass ceramics.
5.Corrosion at grain boundary region plays an important role for static fatigue crack growth in polycrystalline alumina.
6.In sigle crystal sapphire extreme unisotropy was recognized in the cracking behaviors by Vickers indentation.
7.Fracture toughness of various low index planes were evaluated by indentation microfracture (IF) method. As a result, the largest fracture toughness was obtained on C(0001) plane, the second largest on A(1120) plane, the third largest on M(1010) plane and the smallest fracture toughness was obtained on R(1012) plane.
|
