Titnium DIBORIDE is a wear-resistant compound having high hardness, low density and high electrical and thermal conductivity in the solid state. In this study, the explosive POWDER metallurgy process for production of samples from TiB2 POWDER was investigated. At first, analytical solution of the explosive POWDER metallurgy process with water as interface medium was performed in order to determine the suitable explosive material to consolidate the TiB2 POWDER. In the experimental section, with the different design of assemblies the pieces were produced with this method. Analysis of the density and hardness of the produced parts showed that the use of momentum traps with proper height and TITANIUM POWDER in the assemblies, can reduce the shock wave stretching back into the die and produce disks with relative density of 98% and a hardness of 2600 Vickers. In addition, investigation of the microstructure of the produced components using scanning electron microscopy showed that there was a good connection between the POWDER particles and the samples were free of any cracks.

The consolidation of the Al203/TiB2 into a dense and high-strength body is difficult because of the high degree of covalent bonding and low self-diffusion coefficient of the constituent elements. Synthesis of fine and homogenous structure in which one phase homogenously dispersed in the other can resolve this problem. Consolidation of Al203/TiB2 nano-composite POWDER derived from two different synthesis methods was investigated. Also the effect of processing condition on the sintering behavior, microstructure, and hardness of the densified samples were evaluated. In the first synthesis method a composite structure containing of an Al203 matrix with dispersed TiB2 particles was obtained via mechanical alloying of AI, Ti02 and B203 POWDER mixture. In the second method Al203/TiB2 nano­ composite POWDER was prepared from TTIP (TITANIUM tetra iso propoxide) and B203 using a sol-gel method followed by mechano-chemical reduction in the presence of AI. For sample which prepared by milling assisted sol-gel method, vickers hardness value of hot pressed sample at 1500oC was measured as 15.3 GPa and indentation fracture toughness was calculated as 10.1 MPa.m1/2; while for mechano-chemically synthesized sample this parameters are 20 GPa and 11.4 MPa.m1/2 respectively. Analysis of the diffraction pattern of samples revealed the presence of Al203, TiB2, and Al18B4O33 in the samples. Several factors favors the sintering process of the Al203-TiB2 nano-composite particles at low temperature and short time which include; (1) the nanostructured Al203-TiB2 particles, (2) the disordered crystal structure of the POWDER and (3) liquid phase formation of Al18B4O33.

In this research, 3 layer composite weld containing TITANIUM DIBORIDE (TiB2) on low carbon steel (ST37) was carried out through flux cored arc welding via flux cored electrodes containing 100% TiB2 and 50-50 TiB2-Fe. Then, wear and microhardness tests were used for surviving hardness and wear behavior of samples. The obtained results showed that by increasing volume percent of TiB2 in microstructure, the hardness of layers increased. Also, the highest wear resistance belonged to third layer of sample with 50% TiB2 and thereafter, belonged to first layer of sample with 100% TiB2. The scanning electron microscopic investigation of samples wear surfaces indicated that by increasing volume fraction of TiB2 into layers, the depth wear scratches in the third and second layers decreased and segregation of wear debris in these layers increased, compared with first layer. Also, it was found that by increasing the layers, wear mechanism changed from ploughing to cutting.

The effect of adding isopropanol (ISP) to nitrogen as the fluidizing gas on the hydrodynamics of the fluidization of hydrophilic TITANIUM nanoparticles was studied. It was shown by the pressure drop method that adding ISP reduces the minimum fluidization velocity. Wavelet transform of the pressure fluctuations of the bed was employed to identify the hydrodynamic structures. The energy of hydrodynamic structures was evaluated in each fluidization mode. It was shown that ISP reduces the inter-particle attractive forces by replacing the hydroxyl group of the hydrophilic nanoparticles with an alkyl group. Energy and recurrence analyses were used to define the characteristics of fluidization when adding ISP to nitrogen gas. The energy of macro structures increased when using ISP, having indicated a decrease in the number of bubbles and an increase in the bubble size due to the reduction of inter-particle attractive forces. The increase of the white local areas in the recurrence plots also showed the increase of the bubble size. The recurrence quantification analysis showed the increase of the larger-scale phenomena (i. e. bubbles) in the bed.

In this research, DTA and TGA curves of TITANIUM hydride POWDER in air with the heating rates of 5, 10, 20, 25, 30oC/min were drawn, and XRD patterns of TITANIUM hydride POWDER during heating rate 10oC/min were prepared. Results showed that hydrogen comes out of TITANIUM hydride in air during seven stages. And, by increasing heating rate, the mechanism of hydrogen emission from TITANIUM hydride is almost fixed. Upon computation of activation energy of these stages, it was revealed that the mechanism does change at different temperatures. According to DTA curve at 10oC/min, at temperatures lower than 460ºC, the mechanism is controlled by internal diffusion, at temperatures between 460-650oC, it is controlled by physicochemical process, and at temperatures higher than 650ºC, it is controlled by chemical reaction. By increasing heating rate, the mechanism is changed at higher temperatures.

High-temperature ceramics possess significant potential for aerospace, military, and industrial applications due to their unique properties. One such ceramic is the ZrB2-SiC composite, which has garnered considerable attention and extensive research. This study investigated the effect of adding TiB2 on the pressureless sintering behavior, as well as the mechanical, microstructural, and thermal properties of the ZrB2-SiC nanocomposite. For this purpose, TiB2 particles were added in varying amounts of 0, 5, 10, 15, 20, 25, and 30 weight percent, with a constant amount of 3 weight percent B4C, to the ZrB2-15.5 vol.% SiC nano/micron matrix. The resulting POWDERs were ball-milled for 2 hours at 300 rpm. The resulting mixtures were first uniaxially pressed at 100 MPa and then subjected to cold isostatic pressing (CIP) at 200 MPa. The samples were subsequently sintered at 2100°C in an argon atmosphere using the pressureless sintering method. The results indicated that the formation of the solid solution (Zr,Ti)B2 in the compositions led to improvements in the physical and mechanical properties of the samples. The highest properties were observed in the sample containing 30 weight percent TiB2, with a relative density of 96.66%, hardness of 16.74 GPa, and fracture toughness of 4.69 MPa.m1/2. The results also showed that the addition of TiB2 did not improve the oxidation resistance of the samples, with the highest oxidation resistance observed in the sample without TiB2, which had a mass erosion rate of 1.37 mg/s and a linear erosion rate of 1.03 mm/s.

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.