Structure and some properties of sintered tantalum carbide

Microstructure and properties of HfC and TaC-based ceramics obtained by ultrafine powder

“…2a), achieved a maximum densification rate of 3 × 10 −2 min −1 ( Table 1) at 1800 • C and it reached a bulk density of 11.03 g/cm 3 , which corresponds to about 89% of the theoretical density. HfC-MoSi 2 started shrinking at a higher temperature, 1540 • C, but achieved a maximum densification rate of 4.6 × 10 −2 min −1 ( Table 1) at 1870 • C, achieving a final density of 11.80 g/cm 3 , about 93% (Fig.…”

“…[1][2][3] Proposed uses include rocket nozzles and scramjet components, where the operating temperatures can be in excess of 3000 • C. Monolithic TaC or HfC are traditionally difficult to densify due to their highly covalent bonds and low self-diffusion coefficients. Therefore, hot pressing has been typically used to enhance the densification of these compounds.…”

Mechanisms of pore formation in high-temperature carbides: Case study of TaC prepared by spark plasma sintering

“…However, the strengths reported for TaC 1Àx are typically lower than theoretical (100-500 MPa) [5,16,[20][21][22][23][24][25][26], an effect that is well understood for brittle materials and related to pre-existing flaws in the material. Pores are a dominant type of flaw in TaC 1Àx , a consequence of the difficulty in producing dense samples [6,7,22,25,[27][28][29][30][31][32][33][34][35][36].…”

“…Pores are a dominant type of flaw in TaC 1Àx , a consequence of the difficulty in producing dense samples [6,7,22,25,[27][28][29][30][31][32][33][34][35][36]. Grain growth during sintering is often cited as the cause for trapped porosity in the microstructure of TaC.…”

Dynamic Consolidation of TaC and Nano-YSZ Powders (POSTPRINT)

“…For instance, HIP-ing of TaC for 3 hrs at 1900°C at 105 MPa pressure increased the average grain size from 22 to 57 μm [3]. In a separate instance, sintering at 2500°C for 40 minutes led to formation of voids at grain boundaries, and the grain size increased from 0.2 μm to 16 μm [4]. These large grains are detrimental to the fracture toughness and strength of the material.…”