Sintering kinetics, structure, and some properties of heterophase materials of the titanium diboride-tantalum carbide system

Densification and Fracture Responses of (Ta1−xWx)C–WC Composites

“…Unfortunately, each of these studies used five specimens or less, which is considerably lower than the recommended ten according to ASTM C1161. The fracture strengths of the TaC specimens from this study, 114 ± 10 MPa, are most comparable with 130–150 MPa fracture strengths reported by Shvab and Egorov [ 51 ] because of their similar densities (about 80% of theoretical density). The fracture strengths of the 90(Ta 0.8 W 0.2 )C–10WC composite specimens, 362 ± 31 MPa, are comparable with those of high‐density TaC specimens, [ 29,60–63 ] which exhibit fracture strengths from 280 to 660 MPa.…”

“…Equation (5) Figure 3. Nominal fracture strengths of TaC ceramics reported in this study and by others [19,24,25,29,51,[58][59][60][61][62][63] as a function of density, showing density-dependent and flaw-dependent strength regimes.…”

“…[50] This effect can also be seen when TaC is added to TiB 2 , TaC to TiC, and TaSi 2 to HfB 2 -SiC. [51][52][53][54] All of the aforementioned examples probe grain size reduction with respect to the Zener pinning effect, a mechanism common in multiphase carbides. [55] The pinning effect caused by the secondary phase can be determined by…”

“…[ 50 ] This effect can also be seen when TaC is added to TiB 2 , TaC to TiC, and TaSi 2 to HfB 2 –SiC. [ 51–54 ] All of the aforementioned examples probe grain size reduction with respect to the Zener pinning effect, a mechanism common in multiphase carbides. [ 55 ] The pinning effect caused by the secondary phase can be determined bywhere P z is the pinning pressure applied on a unit area of grain boundary by secondary‐phase particles, F is the volume fraction of secondary‐phase particles, γ is the specific grain boundary energy, and r is the radius of the particles.…”