Stress relaxation in zirconium carbide. Report 2. Mechanisms of stress relaxation. The relationship of the processes of creep and relaxation

High-temperature toughening in ternary medium-entropy (Ta1/3Ti1/3Zr1/3)C carbide consolidated using spark-plasma sintering

“…Data of the temperature dependence for the strength of the individual monolithic TaC, TiC, and ZrC carbides are summarized in Figure 6 [31][32][33][34][35][36][37]. Within these monolithic carbides, data for titanium carbide [33,34] show why this monolithic carbide cannot be used for extremely high temperatures.…”

“…The tendencies for ZrC are fully summarized in ref [2]. For the monolithic zirconium carbide ceramics [2,35,39], the transition between the brittle and ductile fracture is associated with a clear maximum. The peak strength for these ceramics is usually observed in the vicinity of the BDTT, but the position of the peak is quite sensitive to (a) grain size and (b) consolidation conditions, i.e., a higher consolidation temperature allows shifting the peak strength to the higher temperatures.…”

“…The flexural strength data of the binary or ternary carbides are limited by [36] and [8]. In [35], the NbC-ZrC solid-solution follows a trend similar to the individual NbC or ZrC. While the data for the ternary (Ta,Zr, Nb)C suggested that the behavior of the ternary ceramic is comparable to the data for the monolithic NbC [31,32] or NbC-ZrC [36] solid-solution, it also suggests that the magnitude for the solid-solution strengthening contribution.…”

“…Effect of temperature on the flexural strength of (Ta 1/3 Ti 1/3 Zr 1/3 )C prepared in this study. (a) provides variation in strength for TTZ ceramic and for selected monolithic carbides[31][32][33][34][35][36][37]. The closed symbols indicate that the strength was measured using a four-point setup and the open symbols show the results of the three-point flexural strength tests.…”

Creep and Oxidation of Hafnium Diboride Based Ultra High Temperature Ceramics at 1500C

“…None of the other works pertaining to the creep behavior of UHTCs include HfB 2 or ZrB 2 as a primary alloy. Several works consider the creep of transition metal carbides, but these materials generally do not possess the desired oxidation resistance [81]- [95]. Since oxidation is one of the key concerns in these works and in the Problem Statement, some review of the topic is warranted.…”