This Article Full Text (PDF) All Versions of this Article: 1045389X07083620v1 19/3/407    most recent References Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Add to Saved Citations Download to citation manager Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Nakao, W. Articles by Ando, K. Search for Related Content Social Bookmarking                   What's this?

Enhancement of In situ Self-crack-healing Efficient Temperature Region by SiC Nanosizing

Faculty of Engineering, Yokohama National University, 79-5, Tokiwadai Hodogaya-ku, Yokohama, 240-8501, Japan, wnakao{at}ynu.ac.jp

Yasuyuki Tsutagawa

Graduate School, Yokohama National University, 79-5, Tokiwadai Hodogaya-ku, Yokohama, 240-8501, Japan

Kotoji Ando

Faculty of Engineering, Yokohama National University, 79-5, Tokiwadai Hodogaya-ku, Yokohama, 240-8501, Japan

Self-crack-healing by oxidation of silicon carbide (SiC) is the most effective method to improve the reliability of ceramics, as this eliminates surface cracks completely. Furthermore, if the service condition corresponds to the state under which self-crack-healing can occur, cracks introduced during service can be completely healed during service. However, the ceramic composites having crack-healing ability exhibit only a small efficient temperature region for crack-healing during service. Therefore, the authors have tried to decrease the temperature at which crack-healing reaction becomes active, as well as to increase the temperature limit for bending strength by size reduction in the contained SiC particles. The present study adapts the following self-propagating high temperature synthesis (SHS) to fabricate alumina composite containing nanosized SiC particles: 3(3Al₂O₃2SiO₂) + 8Al + 6C = 13Al₂O₃ + 6SiC. The formed nanosized SiC particles have a particle size of 10—30 nm and exist in alumina grain. As a result, the temperature at which self-crack-healing becomes active can be decreased 200°C by using SHS. Furthermore, the crack-healed specimen has no large strength decrease up to 1300°C. Therefore, new alumina/ SiC nanocomposite is found to exhibit the in situ self-crack-healing efficient temperature region of 300°C.

Key Words: crack-healing • nanocomposite • self-assemble reaction • reliability.

CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?