Ni-Ti-Al Intermetallic Compounds have been extensively studied in the recent years due to their promising engineering applications specifically in the field of high temperature due to high corrosion resistance and excellent high temperature strength. There are different methods to produce intermetallic compounds. The most widely used of these methods include powder metallurgy, mechanical alloying and SHS. Despite some limitations, mechanical alloying (MA) is one of the best methods for making and production of intermetallic compounds because of low production cost and its simple process. This study primarily aimed at investigating compounds formed during MA of Ni-25Ti-25Al system. As such, the prepared powder mixture was milled. In order to avoid unwanted reactions, mechanical alloying was carried out under argon atmosphere. Moreover, since the final product and its formation speed through MA depends on ball mill energy parameter, this study also examined the effect of ball mill energy on the formation of compounds. This being so, alloying was conducted in planetary ball mill and attritor. Microstructure investigations were made by X-ray diffraction (XRD), Scanning Electron Microscope (SEM), thermal analysis and microhardness surveys. The results revealed that MA of powder mixture led to the formation of Ni 3 (Ti,Al) Nanostructured compounds with irregular L1 2 structure. It was observed that during MA, with the formation of layer structure and diffusion of Ti and Al atoms into Ni lattice, the aforementioned solid solution was created and after continuing the MA, it changed into Ni 3 (Ti,Al). Heat treatment of product under different conditions leads to decomposition of a part of the Ni 3 (Ti,Al) phase to other intermetallic phases. In the end, after heat treatment, an alloy of multiple phases was formed. Heat treatment leads to regulation of Ni 3 (Ti,Al) network and appearance of its superlattice peaks. In order to increase the efficiency of the parts and industrial tools, it is necessary to conduct appropriate surface treatment or coating on the parts; hence, surface engineering is of great importance nowadays. Intermetallic compounds coatings on ferrous and nonferrous substrates have received considerable attention due to resistance to wear and perfect oxidation and relatively lower friction coefficient. Moreover, this study examined the evolution of Ni-Ti-Al intermetallic coating microstructure conducted in APS methods on carbon steel substrate. In order to investigate the effect of thermal spray current on coating, 4 different current (Amp) were used. Appropriate powder for thermal spray was produced by ball mill of powder for 2 hours in attritor ball mill. In order to characterization of coating, various tests were performed on them. The results showed that after the spraying, the Ni 2 TiAl, NiTiAl, Ni solid solution and some TiO 2 were formed. In the coating, an increase in the plasma temperature to a certain degree can lead to a reduction in intermetallic compounds, an increase in porosity, and a decrease in coating hardness. The produced coating with the lowest current intensity has the highest adhesion in substrate and the lowest toughness. According to the results, the produced coating with the lowest current intensity has optimized conditions. Keywords : Ni-Ti-Al intermetallic compounds, Mechanical alloying, Nanostructure Materials, APS