Measurement of thermophysical properties of ceramics by the flash method

Abstract

ABSTRACT

Thermal properties of autoclave and out-of-autoclave carbon fiber-epoxy composites with different fiber weave configurations

“…where C Ã p s is the specific heat calculated by the software where an isotropic density was assumed. Hence, equation (16) was multiplied by a correction factor obtained from equations (12) and (13) in order to include the anisotropic behavior of the density…”

“…Density was measured at room temperature (see Figure 4) for the materials mentioned in Table 1 to obtain the term o of equations (12) and (13). These experiments indicated that different weave configurations affected the composite density because samples made of woven fabrics (PW and 8HS) showed lower values than those measured in UD samples.…”

“…These findings agreed with the literature where it was found that Vf for UD composites 10 was higher (Vf ¼ 50-70%) than that for woven fabrics (Vf ¼ 35-55%). 16,17 Once the density was characterized at room temperature, the next step was to measure the thermal expansion ÁLðTÞ=L 0 of samples oriented in fiber direction (d11) and through-the-thickness (d33) using a TMA in order to obtain the volumetric thermal expansion (equations (12) and (13)). Notice that tests in d22 direction were not performed due to the assumption shown in equations (10) and (11).…”

A novel ANN-based method for simultaneous estimation of thermophysical properties using experimental photothermal data

“…Nowadays, this experiment is still commonly used thanks to standardized LFA (Laser Flash Apparatus) devices. The studies carried out by Min et al [14], Pinto et al [15] and Abdulagatov et al [16] are linked to this experiment. Nevertheless, in order to estimate various properties simultaneously, like for example thermal diffusivity (a) and heat capacity (Cp), another experiment, often DSC (Differential Scanning Calorimetry) must be carried out to determine heat capacity.…”

Effect of film thickness on the temperature dependence of thermal conductivity for diamond/BeO composites

“…The perpendicular thermal conductivity (in the axis direction) of various composites (substrate included) in the temperature range of 298.15-653.15 K were measured by laser flash technique utilizing Netzsch LFA 457 [6], which have been broadly employed to characterize high conductivity materials with either simple or complex structures [7,8], especially in a wide temperature range. The principle of this measurement is utilizing a pulsed laser to heat the front side of plate-shape material and recording the temperature rise versus time on its rear surface, thus we can directly obtain thermal diffusivity D by using equation given in reference [8], and specific heat C by using a comparative method [9].…”