Elastic and thermal properties of Zr 2 Al 3 C 4 : Experimental investigations and ab initio calculations
TL;DR: In this paper, the authors presented the results of combined experimental and theoretical studies of elastic and thermal properties of Zr(2)Al(3)C(4) carbide.
Abstract: This article presents the results of combined experimental and theoretical studies of elastic and thermal properties of Zr(2)Al(3)C(4) carbide. The full set of second order elastic constants, bulk modulus, shear modulus, and Young's modulus of Zr(2)Al(3)C(4) were calculated and compared with those of Zr(3)Al(3)C(5) and ZrC. The experimentally measured Young's modulus and shear modulus are in good agreement with theoretical ones. The calculated Debye temperature from elastic constants of Zr(2)Al(3)C(4) is 830 K, which is slightly higher than that of Zr(3)Al(3)C(5), and exhibits pronounced enhancement in comparison with that of ZrC. The highest Debye temperature of Zr(2)Al(3)C(4) is related with its highest specific stiffness, i.e., the stiffness-to-weight ratio. The heat capacity and thermal conductivity of Zr(2)Al(3)C(4) were measured by means of the flash method. The thermal conductivity of Zr(2)Al(3)C(4) decreases with increasing temperature, for instance the values at room temperature and 1600 K are 15.5 and 10.1 W/m K, respectively. The investigations provide information on elastic and thermal properties of Zr(2)Al(3)C(4) with promising high temperature applications. (c) 2007 American Institute of Physics.
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TL;DR: In this paper, the thermal properties of Y2SiO5 comprehensively, including thermal expansion, thermal diffusivity, heat capacity and thermal conductivity, were investigated, and it was shown that Y(2)SiO(5) is a promising candidate for oxidation resistant or environmental/thermal barrier coatings (ETBC) due to its excellent high-temperature stability, low elastic modulus and low oxygen permeability.
Abstract: Y(2)SiO(5) is a promising candidate for oxidation-resistant or environmental/thermal barrier coatings (ETBC) due to its excellent high-temperature stability, low elastic modulus and low oxygen permeability. In this paper, we investigated the thermal properties Of Y2SiO5 comprehensively, including thermal expansion, thermal diffusivity, heat capacity and thermal conductivity. It is interesting that Y(2)SiO(5) has a very low thermal conductivity (similar to 1.40 W/m K) but a relatively high linear thermal expansion coefficient ((8.36 +/- 0.5) x 10(-6) K(-1)), suggesting compatible thermal and mechanical properties to some non-oxide ceramics and nickel superalloys as ETBC layer. Y(2)SiO(5) is also an ideal EBC on YSZ TBC layer due to their close thermal expansion coefficients. As a continuous source of Y(3+), it is predicted that Y(2)SiO(5) EBC may prolong the lifetime of zirconia-based TBC by stopping the degradation aroused by the loss of Y stabilizer. (C) 2008 Elsevier Ltd. All rights reserved.
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Journal Article•
TL;DR: Y2SiO5 is a promising candidate for oxidation-resistant or environmental/thermal barrier coatings (ETBC) due to its excellent high-temperature stability, low elastic modulus and low oxygen permeability as mentioned in this paper.
Abstract: Y2SiO5 is a promising candidate for oxidation-resistant or environmental/thermal barrier coatings (ETBC) due to its excellent high-temperature stability, low elastic modulus and low oxygen permeability. In this paper, we investigated the thermal properties of Y2SiO5 comprehensively, including thermal expansion, thermal diffusivity, heat capacity and thermal conductivity. It is interesting that Y2SiO5 has a very low thermal conductivity (∼1.40 W/m K) but a relatively high linear thermal expansion coefficient ((8.36 ± 0.5) × 10-6 K-1), suggesting compatible thermal and mechanical properties to some non-oxide ceramics and nickel superalloys as ETBC layer. Y2SiO5 is also an ideal EBC on YSZ TBC layer due to their close thermal expansion coefficients. As a continuous source of Y3+, it is predicted that Y2SiO5 EBC may prolong the lifetime of zirconia-based TBC by stopping the degradation aroused by the loss of Y stabilizer.
102 citations
TL;DR: In this paper, a high-quality carbide interface between the metal matrix and diamond was used to improve the bulk thermal conductivity of composite materials, achieving an ITCDEM of 5·107 Wm−m−2 K−K−1.
102 citations
TL;DR: In this paper, a carbide-metal-intermetallic, multi-layered interface model was established to evaluate the influence of different components and structures of interface layers on the ITC and TC of the surface metallized diamond/Al composites.
81 citations
TL;DR: The layered ternary and quaternary carbides have attracted increasing attentions due to their fascinating properties such as high specific stiffness, high strength and fracture toughness, refractory, machinability by electrical discharge method, thermal shock resistance, as well as high-temperature and ultra-high temperature oxidation resistance as mentioned in this paper.
Abstract: The layered ternary and quaternary carbides in Zr-Al(Si)-C and Hf-Al(Si)-C systems with general formulae of ( T C) n Al 3 C 2 , ( T C) n Al 4 C 3 and (TC) n [Al(Si)] 4 C 3 (where T = Zr or Hf, n = 1, 2, 3…) have attracted increasing attentions due to their fascinating properties such as high specific stiffness, high strength and fracture toughness, refractory, machinability by electrical discharge method, thermal shock resistance, as well as high-temperature and ultrahigh-temperature oxidation resistance. The combination of these properties makes them promising as structural components or coatings for high- and ultrahigh-temperature applications. In this review, the progresses on processing, and structure–property relationships of the novel layered carbides are comprehensively outlined. The crystal structure characteristics are introduced first. Then, methods for processing powders and bulk samples are summarized. The third section focuses on the multi-scale structure–property relationships. Finally, the potential applications and further trends in tailoring the properties and developing low cost processing methods are highlighted.
80 citations
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