1994 Fiscal Year Final Research Report Summary
SYNTHESIS OF AIN BY EXOTHERMIC NITRIDATION REACTION OF AI ALLOYS THROUGH DIFFUSION CHANNEL OF NITROGEN
| Project/Area Number |
05453076
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Inorganic materials/Physical properties
|
|---|
| Research Institution | YOKOHAMA NATIONAL UNIVERSITY |
|---|
Principal Investigator |
KOMEYA Katsutoshi YOKOHAMA NATIONAL UNIVERSITY,FACULTY OF ENGINEERING,PROFESSOR, 工学部, 教授 (30215412)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MEGORO Takeshi YOKOHAMA NATIONAL UNIVERSITY,FACULTY OF ENGINEERING,ASSISTANT, 工学部, 助手 (40134895)
|
|---|
| Project Period (FY) |
1993 – 1994
|
| Keywords | Aluminum nitride / Al alloy / Self-propagating high-temperature synthesis / Nitridation reaction / Lithium |
|---|
| Research Abstract |
Direct nitridation of A1 alloys such as Al-Y,Al-Ca and Al-Li was investigated with particular emphasis on the alloy composition, reaction temperature and reaction time. Although no noticeable reaction was seen for A1-Y alloy and pure Al, the alloys of Al-2.3wt%Li, A1-5.0wt% Li and Al-5.0wt%Ca converted completely to AlN in very short soaking time at 1000ﾟC,and Al-1.0wt%Li and 0.5wt%Li showed conversion ratios of 28.2 and 12.6%at 1000ﾟC for 5h, respectively. The reaction using Al-2.3wt%Li alloy could be divided into three categories : namely, surface nitridation, volume nitridation and breakaway nitridation. In the breakaway nitridation, the product greatly expanded to show no trace of the original form. The inner part consisted of rod-like, plate-like and spherical AlN grains. The size increased with increasing reaction temperature. In A1-1.0wt%Li and A1-0.5wt%Li, the exothermic reaction was not observed during nitridation, which is quite different from the case of higher Li content. The phase in the product from the AlN-1.0wt%Li alloy was composed of AlN,whereas those from AlN-0.5wt%Li was AlN and alpha-A1203. The nitridation mechanism of A1 alloys such as Al-Li and Al-Ca was estimated to be based on the nitrogen diffusion through open channel formed by Li migration to the surface.
|
