High temperature creep behavior of
in-situ synthesized MoSi2-30%SiC composite
in-situ synthesized MoSi2-30%SiC composite
(1. School of Materials Science & Engineering, University of Science &
Technology Beijing, Beijing 100083, China;
2. State Key Laboratory for Advanced Metals and Materials，
University of Scie nce & Technology Beijing, Beijing 100083, China；
3. Department of Materials Science & Engineering, Tsinghua University,
Beijing 1 00084, China)
Technology Beijing, Beijing 100083, China;
2. State Key Laboratory for Advanced Metals and Materials，
University of Scie nce & Technology Beijing, Beijing 100083, China；
3. Department of Materials Science & Engineering, Tsinghua University,
Beijing 1 00084, China)
Abstract: The compressive creep behavior at 1200～1400℃ of an in-situ synthesized MoSi2-30%SiC (volume fraction) composite and a traditional PM MoSi2-30%SiC (volume fraction) composite is investigated. The creep rate of the in-situ synthesized MoSi2-30%SiC (volume fraction) composite is about 10-7s-1 under stress of 60～120MPa, and significantly lower than that made by PM method above 1300℃. The reason is that the interface between SiC particle and MoSi2 matrix in in-situ synthesized SiCp/MoSi2 is of direct atomic bonding without any amorphous glassy phase, such as SiO2 structure. Creep deformation occurs primarily by dislocation motion and the dislocations have Burgers vectors of the type of 〈110〉 and 〈100〉.
Key words: SiC/MoSi2 composite; in-situ synthesis; creep; dislocation