Compressive creep of alloys of the ZrC-ZrB2 and TiC-TiB2 systems

Kats, S. M.; Ordan’yan, S. S.; Unrod, V. I.

doi:10.1007/bf00789205

Cited by 19 publications

(19 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The results of our studies of the physical properties of sintered heterophase composites have revealed their specific features -the high resistance to cracking and wear [12] and superplasticity [13], which, in our opinion, bears relevance to the dimension of phase constituents and to the structural features of interphase boundaries. The involvement of the latter factor is emphasized by the data on heat conductivity of the sintered materials (Fig.…”

mentioning

confidence: 97%

See 1 more Smart Citation

Eutectics and their models, sintered composites, in systems of refractory materials

Ordan’yan

Unrod

2005

Refract Ind Ceram

Self Cite

View full text Add to dashboard Cite

Eutectics and high-disperse systems of noninteracting or thermodynamically incompatible components are considered for their potential use in the design of a wide range of new heterophase ceramics with well-developed interphase boundaries ("coarse-conglomerate" models for eutectics) and their physicomechanical properties and structure-sensitive parameters are analyzed.Oxygen-free refractory compounds -metalloids and covalent-bonded species -recently have been gaining the ever-increasing application in the development of new ceramic materials with superior physicomechanical properties intended for service under heavy-duty conditions in machine building, nuclear power engineering, aircraft engineering, and special technologies. In the second half of the past century, much effort has been put into the study of properties and the development of technologies for these materials. An important achievement in the field of refractory oxygen-free materials was the development of sintering methods such as hot pressing (HP), isostatic hot pressing (IHP) and the theoretical background of a so-called activated sintering.Progress in technology has always been a stimulus for the development of new materials which, in design at least, would combine a set of properties rarely (if ever) found in a single material; a route to successful solution of the problem is provided by developing composite (heterophase) materials. To that effect, a simple and efficient means is the ceramic powder technology. At present, a range of versions of this technology have been proposed which permit the production of complicated ceramic components from precursor powders of different particle size gradation -from 10 to 10 6 nm.State diagrams of n-component systems describing the conditions (temperature and concentration, both varying over a wide range) for refractory materials provide the physicochemical basis for designing composite materials. At present, the number of thoroughly studied ternary state diagrams Me¢-X-Me¢ or Me¢-X¢-X² is rather limited; for the most part, there are data on phase relations and structure of individual isothermal or polythermal cross-sections (here Me refers to transition metals, Al, Si, etc., and X refers to B, C, N, and O).In recent decades, data have been reported in the literature on the interaction between refractory materials of different class; in other words, the structure of polythermal crosssections Me d ¢X¢-Me d¢ X² in ternary systems Me d ¢-X¢-X² (for example, Me d C-Me d B 2 , Me IV N-Me IV B 2 , Me d C-SiC, etc.).Based on generalized data from the literature [1] and applying a trial tetrahedration method to quaternary (yet-unstudied) systems Me¢-Me¢¢-X¢-X¢¢ and Me-X¢-X¢¢-X¢¢¢, a classification for quasi-binary systems has been proposed that can help lay down the guidelines for the preparation of heterophase materials for various applications (Fig. 1). It is important to indicate that the majority of these systems can be described by state diagrams of the eutectic type. So, the systems, and SiC-Me d C [9] are eut...

show abstract

mentioning

confidence: 97%

“…This fact emphasizes that the mechanism for formation of coherent interphase boundaries can be used to explain the unique properties of both the eutectics and their sintered "coarse conglomerate" composites. It should be noted that, at high temperatures, these composites exhibited superplasticity effects [12].…”

mentioning

confidence: 99%

Eutectics and their models, sintered composites, in systems of refractory materials

Ordan’yan

Unrod

2005

Refract Ind Ceram

Self Cite

View full text Add to dashboard Cite

show abstract

“…Most of the previous efforts employ flexural setups for mechanical testing, for example, Guo [10], Kats [11], and Spivak [12]. These methods add some assumptions and special considerations when extending the results to other types of loading and make the determination of the underlying creep mechanisms more difficult.…”

Section: What Are the Creep Rates And Creep Mechanisms Associated Witmentioning

confidence: 99%

“…Grain size is identified as a strong factor, and creep mechanisms are not discussed. Kats et al [11] take a look at the flexural creep of TiB 2 and ZrB 2 in helium with varying additions of TiC and ZrC, respectively, with data in a temperature range from 1700 to 2420˚C and stress levels from 5 to 30 MPa. These works should be recognized for their early and motivational investigations into the creep performance of UHTCs.…”

Section: ( 8 )mentioning

confidence: 99%

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

DeGregoria¹

2015

View full text Add to dashboard Cite

Ultra high temperature ceramics (UHTCs) are leading candidates for aerospace structural applications in high temperature environments, including the leading edges of hypersonic aircraft and thermal protection systems for atmospheric re-entry vehicles.Before UHTCs can be used in such applications, their structural integrity and environmental durability must be assured, which requires a thorough understanding and characterization of their creep and oxidation behavior at relevant service temperatures.Creep, or the progressive, time-dependent deformation of material under constant load, is a critical criterion in these applications, but not much is known with regard to UHTCs or whether there are interactions with oxidation processes. Thus, a facility for high temperature, mechanical testing in air was augmented for testing in argon. Then, the compressive creep of a popular UHTC, HfB 2 , was examined at 1500°C in argon and compared to results in air. HfB 2 specimens with 0, 10, 20, and 30% additions of SiC were tested, which enabled assessments of the effects of grain size and SiC content on creep behavior. Boundary mechanisms accommodated by diffusion through grains dominated the creep rates. The results also suggest that SiC formed a network of pointto-point contacts and increased creep resistance.A unique stressed oxidation test was devised in order to further investigate the interaction of creep and oxidation. The results indicate that up to 75 MPa of compressive stress, models of creep and oxidation in HfB 2 -based UHTCs can be decoupled.

show abstract

“…No experimental tensile data are available in the literature for direct comparison. In fact, for ZrB 2 composites, only flexure and compression experiments were carried out in the literature [7,[18][19][20][21][22][23]. Additionally, we propose an enhanced specimen geometry for compression creep testing that allows higher creep strains to be reached prior to the onset of catastrophic specimen instability.…”

Section: mentioning

confidence: 99%

Prediction of tensile power law creep constants from compression and bend data for ZrB2–20 vol% SiC composites at 1800 °C

2017

View full text Add to dashboard Cite

Abstract:Here we consider our four-point flexure and compression creep results obtained under Ar protection at 1800 ℃ to predict the tensile creep behavior of a ZrB 2 -20 vol% SiC ultra-high temperature ceramic. Assuming power law creep, and based on four-point bend data, we estimated the uniaxial creep parameters using an analytical method present in the literature. Both predicted and experimental compressive stress exponents were found to be in excellent agreement, 1.85 and 1.76 respectively, while observation of the microstructure suggested a combination of diffusion and grain boundary sliding creep mechanisms in compression. Along with the microstructural evidence associated with the tensile regions of the flexure specimens, the predicted tensile stress exponent of 2.61 exceeds the measured flexural value of 2.2. We assert an increasing role of cavitation to the creep strain in pure tension. This cavitation component adds to the dominant grain boundary sliding mechanism as described below and elsewhere for flexural creep.

show abstract

Compressive creep of alloys of the ZrC-ZrB2 and TiC-TiB2 systems

Cited by 19 publications

References 1 publication

Eutectics and their models, sintered composites, in systems of refractory materials

Eutectics and their models, sintered composites, in systems of refractory materials

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

Prediction of tensile power law creep constants from compression and bend data for ZrB2–20 vol% SiC composites at 1800 °C

Contact Info

Product

Resources

About