Topic
Thermal expansion
About: Thermal expansion is a research topic. Over the lifetime, 21040 publications have been published within this topic receiving 349407 citations. The topic is also known as: heat expansion.
Papers published on a yearly basis
Papers
More filters
Journal Article•
217 citations
TL;DR: In this paper, two SiC-containing metal diborides materials, classified in the ultra-high-temperature ceramics (UHTCs) group, were fabricated by hot-pressing.
Abstract: Two SiC-containing metal diborides materials, classified in the ultra-high-temperature ceramics (UHTCs) group, were fabricated by hot-pressing. SiC, sinterability apart, promoted resistance to oxidation of the diboride matrices. Both the compositions, oxidized in air at 1450°C for 1200 min, had mass gains lower than 5 mg/cm2. Slight deviations from parabolic oxidation kinetics were seen. The resistance to thermal shock (TSR) was studied through the method of the retained flexure strength after water quenching (20°C of bath temperature). Experimental data showed that the (ZrB2+HfB2)–SiC and the ZrB2–SiC materials retained more than 70% of their initial mean flexure strength for thermal quenchs not exceeding 475° and 385°C, respectively. Certain key TSR properties (i.e., fracture strength and toughness, elastic modulus, and thermal expansion coefficient) are very similar for the two compositions. The observed superior critical thermal shock of the (ZrB2+HfB2)–SiC composite was explained in terms of more favorable heat transfer parameters conditions that induce less severe thermal gradients across the specimens of small dimensions (i.e., bars 25 mm × 2.5 mm × 2 mm) during the quench down in water. The experimental TSRs are expected to approach the calculated R values (196° and 218°C for ZrB2+HfB2–SiC and ZrB2–SiC, respectively) as the specimen size increases.
217 citations
TL;DR: In this article, the anisotropic elastic and thermal properties of layered compounds in the series Ln 2 SrAl 2 O 7 (Ln = La, Nd, Sm, Eu, Gd or Dy) are calculated from first principles using density functional theory combined with the Debye quasi-harmonic approximation.
216 citations
TL;DR: In this paper, high-temperature x-ray diffraction was used to study the tetragonal distortion as a function of temperature (25-700 °C) for compositions (x = 0.7) using powders prepared by solid-state reaction in the above system.
Abstract: Compositions in the (Pb1−xBix (Ti1−xFex)O3 solid solution system for x ⋚ 0.7 show unusually large tetragonal distortion. High-temperature x-ray diffraction was used to study the tetragonal distortion as a function of temperature (25–700 °C) for compositions (x = 0–0.7) using powders prepared by solid-state reaction in the above system. Large changes in the lattice parameters were observed over a narrow temperature range near Curie temperature (TC) for compositions near the morphotropic phase boundary (MPB) (x ≃ 0.7). Compositions near MPB showed a c/a ratio of 1.18 at room temperature. Polar plots of lattice constants at different temperatures indicated strong anisotropic thermal expansion with zero thermal expansion along the [201] direction.
216 citations
TL;DR: In this article, the authors explore the range of thermal expansion coefficient attainable in materials with microstructure, including composites, honeycombs, and foams, and explore the constitutive equation for a linear isotropic thermoelastic continuum.
Abstract: Thermal expansion of materials is of considerable practical interest since materials in service may experience a considerable range of operating temperature. Materials with microstructure, including composites, honeycombs, and foams (which are composites with one void phase) are finding increasing application for many purposes. It is therefore of interest to explore the range of thermal expansion coefficient attainable in materials with microstructure. The constitutive equation for a linear isotropic thermoelastic continuum is [1]:
216 citations