TEM investigation of hot pressed ‐10 vol.%SiC–ZrB ₂ composite

Abstract

AbstractThe polytypism of SiC, phase transformation of ZrB2 and the interfaces between SiC and ZrB2 were investigated using high resolution TEM in a hot pressed 10 vol.%SiC‐ZrB2 composite. In most cases, no grain boundary interphases between hexagonal ZrB2 and 6H‐SiC phases were observed with SiC being both inter‐ and intragranular. Occasionally, 6H‐SiC transformed into 3C and 15R and hexagonal ZrB2 transformed into cubic ZrB. High resolution TEM showed no grain boundary interphases in most regions. Energy dispersive X‐ray spectroscopy and electron energy‐loss spectroscopy analyses showed the presence of oxygen throughout the sample. The phase transformation of SiC and ZrB2, and the interphase formation between SiC and ZrB2 grains are discussed.