Effect of zirconia and iron on the mechanical properties of Al2O3/TiC composites processed using combined self-propagating synthesis and direct consolidation technique

Abstract

Self-propagating high temperature synthesis combined with direct consolidation technique was used to synthesize high density Al 2 O 3 /TiC composites from mixture of TiO 2 , Al and graphite powders. The effect of controlled amount of zirconia and iron addition on the density, microstructure and the mechanical properties of the composites was investigated. The results revealed that, addition of either 1.0 mole zirconia or 5.0 wt% of iron metal powder led to a significant decrease in the sample porosity from 7.0 to less than 1.0 vol% together with a remarkable enhancement in the microhardness from 6.0 to 11.0 and 12.0 GPa with 1.0 mole zirconia and 5.0 wt% iron additions, respectively. Moreover, the fracture toughness increased from 3.5 to 6.0 and 7.0 MPa.m 1/2 with 1.0 mole zirconia and 15 wt% iron additions, respectively. However, addition of 1.0 mole zirconia with 5.0 wt% iron powder led to a composite with higher porosity and reduced mechanical properties.

Real-Time Measurement on the Heat Release Property of Titanium Blended with Different Carbon Allotropes, under Externally Constant Heat Flux

“…Table 1 lists the heat-releasing parameters of samples, the S4 comprised of EG and Ti exhibits the highest FGI value of 0.42 kW·m −2 ·s −1 , while the S3 presents the lowest FGI of 0.08 kW·m −2 ·s −1 (the same to that of S5), implying that the CB or VG inhibits the flame propagation effectively [14,15]. Because the EG transforms into fluffy worm-like structure with a vigorous expansion, it facilitates the propagation of combustion wave and heat transfer further due to the loose and fluffy stacking, which favors an extremely vigorous and energetic process [17], evidenced by the decrease in TTI and the rapid increase in HRR. However, the mercerization of NaOH favors the purification of carbon allotropes; the impurities could have transformed combustible volatiles and produced a higher heat release, evidenced by the decrease in the THRs for samples with carbons after NaOH-impregnation.…”

Synthesis of new Cr2O3/Fe2O3/glass composites from industrial wastes; from undesired to advanced optical products

“…Furthermore, it was reported that combining glass and ceramic materials together in one composite structure results in a new polycrystalline material with desirable properties and tailored applications (Ahmed et al 2017 ; Besisa and Ewais 2019 ). The type and properties of the inserted ceramic materials can determine the final characteristics and the new applications of the original glass (Sandu et al 2017a , b ).…”