Absorption Coefficient of Aluminium Oxide

Abstract

The absorption coefficient of aluminium oxide is one of the most important parameters to consider when using laser ignition modeling, because the value of the absorption coefficient depends on the wavelength and temperature. A large number of physicochemical processes influence this value, such as adsorption and desorption, chemical reactions, and so on. Moreover, the optical properties are influenced by both particle size and the surface morphology of the composite material.

A range of thermal transport properties and absorption coefficients for consolidated Al powder compacts were examined through laser flash analysis techniques coupled with COMSOL Multiphysics(r). For bulk densities from 1.1 to 2.3 g/cm3, thermal conductivity was found to increase with density.

In addition, acoustic transport was also investigated. Quasi-static compressive stress-strain curves were obtained for EP, EP/GO, OCF-EP, and OCF-EP/GO specimens at 0.1 mm/s loading rate (Figure 8a) and 1 mm/s loading rate (Figure 8b).

The results show that the OCF-EP and OCF-EP/GO nanocomposite hybrid structures exhibit similar stress-strain behavior to empty aluminum tubes. Compared with the empty aluminum tube, the OCF-EP and OCF-EP/GO demonstrate higher sound absorption coefficients, especially at low frequencies.

The RGO-ZnO hybrid structure shows the highest nonlinear absorption coefficient b of 31.9 x 10-10 cm/w. This can be attributed to the effective reduction of GO moiety to RGO, which enhances the absorption coefficient.