Synthesis, consolidation and characterization of monolithic and SiC whiskers reinforced HfB2 ceramics

Low temperature synthesis of dense and ultrafine grained zirconium diboride compacts by reactive spark plasma sintering

“…The relative density and MIP results of Zr-B-1400C50 sample showed complete densification could not be achieved even after processing at high temperature with applied pressure of 50 MPa. It was reported by previous researchers [3,11] that significant improvement in densification was observed when the applied pressure increased immediately after the in situ reaction. Musa et al [11] have, however, observed that increase in pressure to 60 MPa after the reaction, gave rise to less dense compacts.…”

“…It is reported that an adiabatic temperature of above 3000°C is obtained during the reaction which is sufficient to form 100% ZrB 2 [5]. The formation of ZrB 2 results in sudden shrinkage which has been observed during the simultaneous synthesis and densification of UHTCs [3,6,11,12]. This is the first stage of densification and contributes towards major fraction of the total density.…”

The effect of pitch-based carbon fiber microstructure and composition on the formation and growth of SiC whiskers via reaction of such fibers with silicon sources

“…SiC whiskers (SiCw) have attracted considerable attention due to their excellent mechanical, electrical and optical properties, and they are extensively used for reinforcing advanced composites with various matrices and in electronic devices, operating under extremely harsh conditions [1][2][3][4][5][6][7][8][9][10]. Due to the great interest in silicon carbide whiskers for materials technology, numerous methods have been developed to prepare SiC whiskers, including pyrolysis of polyureasilazane precursor [11], carbon nanotube-confined reaction [12], chemical vapor deposition [13], sol-gel synthesis [14,15], carbothermal reduction [16,17], and direct chemical reactions [18].…”

Phase and Microstructural Correlation of Spark Plasma Sintered HfB2-ZrB2 Based Ultra-High Temperature Ceramic Composites

“…On the other hand, further addition of CNT (i.e., HZ20S6C), increases the densification to~99.5% which is attributed to the high thermal conductivity of CNT [12,32]. Moreover, carbon has long been used as a sintering aid for the densification of a ceramics, and it is often proposed that incorporation of carbon removes the native oxides on the surfaces of the non-oxide ceramics by interfacial reactions and promotes the densification [15]. …”