Structure and Properties of Ni˗Al˗Ti Systems Formed by Combustion Synthesis

Ni-Al-Ti system is one of the intermetallic systems that attract wide interest for high-temperature application. In this work, combustion synthesis was used to produce intermetallic materials prepared by Ni/Al with varied Ti content using 3%, 10%, 20%, and 30%. The reactant mixtures were compressed in a steel die to form compacted pellets. The ignition of the combustion process was conducted using an arch flame. Sequential tests of SEM, EDS, and XRD were conducted to characterize the microstructure of the synthesized products, whereas the mechanical properties of the product were measured using a Vickers microhardness test and wear test. The result shows that the phases formed in the product were dominated by Ni-Al and Ti-Ni systems. An increase in the Ti content from 3% to 20% increases the hardness. The formation of several intermetallic phases was responsible for the harder products. An increase of Ti content decreases the wear rate. This work shows that the content of 10% Ti can be used to achieve the optimized properties of hardness and wear resistance.