Purpose
This paper aims to promote a strength model for TiC-TiB2 composite ceramic with non-ellipsoidal particles bridging. Based on the microstructure of TiC-TiB2 composite ceramic, equivalent ...average residual stress under particles interaction is calculated with the interact direct derivative estimate. Supposing the crack opening displacement keeps ellipsoidal under the TiB2 particles bridging, crack growth resistance curve is obtained.
Design/methodology/approach
Composite strength under R-cure with crack unstable propagation is calculated. Based on this model, influences of particles volume fraction, shape, size and other parameters on strength are analyzed.
Findings
Results indicated that calculated values are consistent to the tested data. Crack growth resistance increases with crack propagation and TiB2 volume fraction. The TiB2 particle does not pull-out entirely even ceramic fracture. Ceramic strength increases with the TiB2 particle volume fraction, the ratio of platelet diameter and thickness, and it reduces with particle thickness.
Originality/value
Supposing the crack open displacement keeps ellipsoidal under the TiB2 particles bridging, crack growth resistance curve is obtained.
The effects of Mn content on the microstructure and mechanical properties of TiC/TiB2 base cermets were studied with the compositions of TiC/TiB2–24Ni (mass%). The TiC and TiB2 ratio is set to a ...molar ratio of 57:43 that is near the quasi–eutectic composition. The cermet exhibits a microstructural refinement with an addition of Mn. Both transverse rupture strength and hardness of the cermet show maximum of 903 MPa and 92.6 HRA for the cermet containing 1.0 vol.% of Mn respectively.
Display omitted
► We studied the effects of Mn content on TiC/TiB2 base cermets. ► The cermet shows a microstructural refinement with an addition of Mn. ► The sintering behavior shows at its best with 1.0 vol.% of Mn addition. ► Transverse rupture strength is 903 MPa and hardness is 92.6 HRA.
Enlightened by the nacreous layer of shell, this study successfully fabricated the bionic composite material using self-propagating high-temperature synthesis (SHS) reaction in the 40wt.% Cu–Ti–B4C ...system during manganese steel casting. The phase constituents, microstructures and wear resistance of the bionic composite material were investigated. The results show that bionic composite material was alternant combination of manganese steel matrix and unit region in a relatively large dimension. Excellent metallurgy bonding between the unit region and steel matrix in the bionic composite material was presented. The results analyzed with X-ray diffraction (XRD) reveal the existence of TiC, TiB2, Cu and austenite without any intermediate phases in the unit region. Due to sufficient infiltration of the melted steel, the unit region had the fewest macro-pores and blowholes. This indicates that the near fully dense bionic composite material can be fabricated. The wear tests show that the wear resistance of the bionic composite material fabricated was better than that of the pure manganese steel.
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