Role of hot-pressing temperature on densifi cation and microstructure of ZrB2-SiC ultrahigh temperature ceramics

Nguyen V., Delbari S. A., Asl M. S., Namini A. S., Kakroudi M. G., Azizian-Kalandaragh Y., ...Daha Fazla

INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS, cilt.93, 2020 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 93
  • Basım Tarihi: 2020
  • Doi Numarası: 10.1016/j.ijrmhm.2020.105355
  • Dergi Adı: INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, INSPEC, Metadex, Civil Engineering Abstracts
  • Anahtar Kelimeler: ZrB2, SiC, Hot-pressing, TEM, Densification, Microstructure, MECHANICAL-PROPERTIES, COMPOSITES, BEHAVIOR, PARAMETERS, RESISTANCE, EVOLUTION
  • Gazi Üniversitesi Adresli: Hayır

Özet

This examination is aimed to study the various densification mechanisms in the ZrB2-SiC system at different sintering temperatures. For such an objective, hot-pressing process was implemented to fabricate three ceramics at sintering temperatures of 1650, 1850, and 2050 degrees C under 10 MPa for 1 h. According to the results, particle rearrangement and fragmentation were the predominant densification mechanisms at the lowest sintering temperature. Additionally, it was found that the activation of the liquid phase sintering mechanism was advantageous in the particle rearrangement at low temperatures. However, rising the sintering temperature to 1850 degrees C changed the dominant mechanism to the plastic deformation. Such a phenomenon was accompanied by the creation of many dislocations in both ZrB2 and SiC grains. Implementing a higher sintering temperature (2050 degrees C) activated another consolidation mechanism called diffusion. This occurrence, together with the evaporation of the majority of the liquid phase at elevated temperatures, resulted in emerging transgranular fracture mode in the sample.