In this research, development of novel Ti-Ni Intermetallic coatings on carbon tool steels has been investigated. For this purpose, nickel coatings as thickness of 20 mm were electrodeposited on steel specimens.Subsequently precoated specimens were titanized for a period of 6hs in an optimized pack cementation mixture of ferrotitanium, aluminium oxide, and ammonium choloride. In order to obtain the optimum Intermetallic coatings and to reduce the compositional and hardness profile gradients, diffusion annealing process was performed on the specimens in an argon- controlled atmosphere. The microstructure and the phases developed in the coating were identified by metallography, microhardness, X-ray diffraction, and glow discharge optical spectroscopy techniques. Experimental results indicated that six distinct layers had been developed on the surface. The Intermetallic compound layer of Ti2Ni was formed on the first surface and TiNi, TiNi3, TiNi , Ti2Ni+Ti(a) and FeNi compound layers formed werre beneath the surface.

High entropy Intermetallic compounds (HEICs) are an interesting class of materials combining the properties of multicomponent solid solutions and the ordered superlattices in a single material. In this work, microstructural and magnetic properties of (CoCuFeMnNi)Al, (CoCuFeMnNi)Zn3, (FeCoMnNiCr)3Sn2, (FeCoNiMn)3Sn2 and Cu3(InSnSbGaGe) HEICs fabricated by induction melting are studied. The magnetic properties of the HEICs was determined mainly by the nature of the magnetic momentum of the constituent elements. (CoCuFeMnNi)Al and (CoCuFeMnNi)Zn3 displayed ferromagnetic behavior at 5 K, while indicated linear dependency of magnetization vs. magnetic (i.e. paramagnetic or antiferromagnetic state) at 300 K. The magnetization of (FeCoMnNiCr)3Sn2, (FeCoNiMn)3Sn2 and Cu3(InSnSbGaGe) HEICs at 300 K exhibited a nearly linear dependency to magnetic field. Among all the investigated samples, (CoCuFeMnNi)Al exhibited the best magnetic properties with a saturation magnetization of about Ms = 6.5 emu/g and a coercivity of about Hc = 100 Oe.

Combustion synthesis is a special thermophysico-chemical process applied for production of Intermetallic compounds. In the present work, a reaction–diffusion numerical model was developed to analyze the combustion synthesis of aluminide Intermetallics by self-propagating high-temperature synthesis process. In order to verify the reliability of the numerical model, an experimental setup was designed and used to perform the combustion synthesis of nickel and titanium aluminides. The developed model was further used to determine the temperature history of a powder mixture compact during self-propagating high-temperature synthesis. The effect of compact relative density on combustion temperature and wave propagation velocity was also studied.

Lap joints of commercially pure magnesium plates to aluminium plates (Magnesium plate on the top, and Aluminium plate, grade 1100, on the bottom side) were conducted by friction stir welding using various traveling and rotation speeds of the tool to investigate the effects of the welding parameters on the joint characteristics and strength. Defect-free lap joints were obtained in the welding traveling speed range of 40-80 mm/min, and rotational speed range of 1200-1600 rpm. The shear tensile strength of Mg/Al joints increased as a result of decreasing the welding speed from 120 to 40 mm/min at constant rotation speed of 1600 rpm. Defects such as surface grooves, excessive flash, tunnels, and voids were observed if the joints prepared out of the mentioned range. The effects of the welding parameters are discussed metallographically based on observations with optical and scanning electron microscopes.

From scientific and technical point of view, Solid-liquid interface reaciton in Iron- Aluminium binary system is important. Expect early transient stage of contact, the dissolution, formation and growth of Intermetallic layer occurs in accordance with kinetic and thermodynamic considerations. These reactions were studied through immersion of Iron samples in liquid Aluminium at different time and temperature. The kinetic of reaction and interface microstructure were results indicate when there is little dissolution, the kinetic of reaction obeys a parabolic growth with a negative deviaiton.Although based on thermodynamic concept, FeAl3is a preferable phase but interface reaction produced two layers include the major thick Fe2 Ais and the minor thin FeAl3 layer that the later compound exists between Aluminium and Fe2 Ais phase.

In this research, the nickel oxide was dissolved in cryolite at temperatures of 880, 940 and 1000oC. In order to reduce the nickel oxide, aluminum was added to the salt. Simultaneously the nickel oxide was reduced and Al3Ni2 Intermetallic compound was formed. In the duration intervals of 2.5-40 minutes samples of the salt and metallic phases were taken. The variation of the nickel content in metallic and salt samples was determined by the AAS. The results indicate that increasing the temperature and duration has a positive effect on the reduction process and Al3Ni2 Intermetallic compound formation. The nickel content in the metallic sample has its highest amount at 1000oC in 10 minutes. Furthermore, practical results of the studies of nickel content variations in metallic and salt samples confirm the data obtained from theoretical calculations.

Ni and Al elemental powder mixture with composition Ni75Al25 were mechanically alloyed in a planetary ball mill under different conditions. The structural changes of powder particles were studied by x-ray diffractometry and scanning electron microscopy. Mechanical alloying for ≈ 10h resulted in a solid solution of Al in Ni which transformed to Ni3Al Intermetallic compound with nanocrystalline structure after≈ 20h of milling time. Decreasing ball-to-powder weight ratio or rotation speed of mill, drastically retarded the formation of Ni3Al phase. However, decreasing size of balls, while the balls-to-powder weight ratio remained constant, did not change mechanical alloying process significantly.      

Based on the crystal and magnetic structural properties of some Gd Intermetallic compounds, it is shown that with increasing conduction electron concentration, Gd experiences electronic and magnetic instability, and that these behaviors point to the appearance of Kondo Lattice. We suggest that the conduction electrons have gained local character. It is shown that Kondo effect should be observed at around x=0.4. Resistivity studies confirm the calculations, and a Kondo temperature of around 70 K found for Gd2Au0.4Al0.6.

The elimination of the FexAly type phases was considered the solution to low ductility presented in aluminum-steel welded joints. Recently, the researches do not seek the suppression but the control of the thickness of these compounds. In this work, Al-Fe joints were manufactured by solid state and fusion welding, looking for controlling the formation of Intermetallic compounds. Temperature measurements were carried out during the welding. The joints interface was characterized using optical and scanning electronic microscopy, aided by chemical composition measures with X-EDS. The microstructural characterization at the interface of aluminum-steel joints, in solid state welded joints, demonstrated the absence of Intermetallic compounds, which is attributed to the low temperature reached during the process-less than 300 ° C. In the case of fusion joints, it has observed the permanent formation of Intermetallic compounds whose thickness varies significantly with the heat input.