Investigation of radiation properties of particles in gas after welding procedure

The radiative properties of hematite (α-Fe2O3) samples of different particle size distributions and compositions obtained by the pressure welding procedure were investigated. Measurements were made in the ultraviolet and visible spectra, and the radiative properties of samples were assessed using the discrete dipole approximation (DDA) in the visible spectrum. In this thesis, the two samples which have different chemical properties were called as Durum 1 and Durum 2. The coating on particles due to the aging effect was examined using scanning electron microscopy (SEM) images. The samples were found to contain hematite phares in the content analysis by X-ray diffraction (XRD). The measured absorbance values of the samples displayed significant differences in the wavelength range of 200-500 nm. Among the measured absorbance of three samples with sizes of 37 μm, 63 μm and 125 μm, the most prominent change in absorbance was observed in the sample consisting of the smallest diameter (37 μm); the 125 μm samples had the highest absorbance values in the spectrum range. Both the experimental and calculated results presented in this study indicate that the absorption behaviour of hematite particles depends on the particle size and coating contents. The radiative properties of Durum 2 are higher than Durum 1.