The wettability of AIN, AIN-BN and A12O3 by molten steel has been studied using sessile drop method. All of the substrates presented non -wetting behaviour after one hour contact with the liquid alloy at 1550°C. The evaluation of liquid-vapour and solid-liquid tensions and the values of adhesion work showed that wetting is governed by chemical interactions at solid -liquid and liquid vapour interfaces. Addition of BN to AIN substrate on one hand reduces its densification rate and on the other hand modifies its wettabilty by molten steel.

We have grown TiO2 and AlN under ultra high vacuum and high pressure conditions and studied their structures with using AES and SEM techniques. The obtained results show that an amorphous film of TiO2 and AlN could be formed on silicon substrate. Furthermore, TiO2 and AlN are high– K dielectric materials and they can thus be replaced to ultra thin gate oxide film.

In this research study, the effects of aluminum nitride (AlN) additive on the densification behavior and microstructure development of titanium diboride (TiB2) based ceramic matrix composite were investigated. In this way, a monolithic TiB2 ceramic and a TiB2– 5 wt% AlN ultrahigh temperature ceramic composite were fabricated by spark plasma sintering (SPS) process at a temperature of 1900 ° C for a dwell time of 7 min under an externally applied pressure of 40 MPa in vacuum conditions. The relative density measurements were carried out using the Archimedes principles for evaluation of bulk density and rule of mixtures for calculation of theoretical one. Compared to the additivefree monolithic TiB2 ceramic sample with a relative density of ~96%, the addition of AlN as a sintering aid greatly improved the sinterability of TiB2 matrix composite so that a near fully dense sample with a relative density of ~100% were obtained by the spark plasma sintering process. The removal of harmful oxide impurities of titania (TiO2) and boria (B2O3) from the surfaces of starting TiB2 powder particles and in-situ formation of new phases such as aluminum diboride (AlB2) and Al2Ti as an intermetallic compound of aluminum and titanium, not only improved the sinterability of the composite ceramic, but also significantly prevented the extreme growth of TiB2 grains.

We have investigated the electronic and optical properties of AlN hexagonal nanosheets under different kinds of strains, using the band structure results obtained through the full potential linearized augmented plane wave method within the density functional theory. The results show that 10% uniaxial strain along the zig-zag direction induces an indirect to direct band-gap transition. The dielectric tensor and corresponding optical properties are derived within the random phase approximation. Specifically, the dielectric function, reflectivity and refractive index of AlN nanosheets are calculated for both parallel ( ) and perpendicular ( ) electric field polarizations.

The adsorption behavior of ethyl acetylene (C4H6) molecule with external surface of (5, 0), zigzag aluminum nitride nanotube (AlNNT) was studied using density functional calculation, and it was found that the adsorption energy (Ead) of ethyl acetylene on the surface of pristine nanotubes is about-10.85 kcal/mol. However, when nanotubes have been doped with a P atom, the adsorption energy of ethyl acetylene molecule was decreased.Calculation showed when the nanotube is doped by P atom, the adsorption energy range is about-8.05 to -10.64 kcal/mol, and the amount of HOMO/LUMO energy gap (Eg) will reduce significantly. Pristine AlNNT is a suitable adsorbent for ethyl acetylene and can be used in separation processes or adsorption of ethyl acetylene toxic gas from environmental systems. Also the AlNNT doped by P in the presence of ethyl acetylene, an electrical signal is generated directly and therefore can potentially be used for ethyl acetylene toxic gas sensors for detection in environmental systems.