Abstract
Microstructure, mechanical properties and toughening mechanisms of hot pressed SiC w Al 2O 3 ceramic composites were investigated by means of XRD, SEM, TEM and EPMA. Experimental results show that fracture toughness and Vickers hardness of composites increase with increasing SiC w content. With 20%(wt) whiskers a fracture toughness of 9 MPa/ m was obtained which is nearly twice that of the matrix. Grain size of the matrix has also an influence on fracture toughness and an increment of 1 to 2 MPa/ m was obtained when the grain size increased from 0.05 to 0.5 um. TEM observation reveals that in most cases no glassy phase exists along the whisker/matrix boundaries but at certain interfaces small traces of glassy phase containing Al and Si were formed. Whisker pull-out and bridging as well as crack deflection are considered to be the main toughening mechanisms. The existence of glassy phase decreases the interfacial bonding strength and thus facilitates the pull-out of whiskers.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
