Titanium carbide (TiC) reinforced nickel (Ni) matrix composites were processed via mechanical alloying (MA) followed by spark plasma sintering (SPS) process. Mechanical alloying has gained special attention as a powerful non-equilibrium process for fabricating amorphous and nanocrystalline materials, whereas spark plasma sintering (SPS) is a unique technique for processing dense and near net shape bulk alloys with homogenous microstructure. TiC reinforcement varied from 5 to 50 wt.% into nickel matrix to investigate its effect on the microstructure and mechanical behavior of Ni-TiC composites. All Ni-TiC composites powder was mechanically alloyed using planetary high energy ball mill with 400 rpm and ball to powder ratio (BPR) 15:1 for 24 h. Bulk Ni-TiC composites were then sintered via SPS process at 50 MPa pressure and 900–1200 °C temperature. All Ni-TiC composites exhibited higher microhardness and compressive strength than pure nickel due to the presence of homogeneously distributed TiC particles within the nickel matrix, matrix grain refinement, and excellent interfacial bonding between nickel and TiC reinforcement. There is an increase in Ni-TiC composites microhardness with an increase in TiC reinforcement from 5 to 50 wt.%, and it reaches the maximum value of 900 HV for Ni-50TiC composites.

Titanium (Ti) is widely used in structural, maritime, aerospace, and biomedical applications because of its outstanding strength-to-weight ratio, superior corrosion resistance, and excellent biocompatibility. However, the lower surface hardness and inferior wear resistance of the Ti and Ti alloys limit their industrial applications. Coating Ti surfaces can initiate new possibilities to give unique characteristics with significant improvement in the Ti component’s functionality. The current research designed and synthesized titanium nitride (TiN), titanium carbide (TiC), titanium carbonitride (TiCN), tantalum nitride (TaN), and niobium nitride (NbN) ceramic coating layers (400 µm) over a Ti substrate using a spark plasma sintering process (SPS). The coatings on the Ti substrate were compact and consolidated at an SPS temperature of 1500 °C, pressure of 50 MPa, and 5 min of holding time in a controlled argon atmosphere. Microstructure investigation revealed a defect-less coating-substrate interface formation with a transition/diffusion zone ranging from 10 µm to 20 µm. Among all of the ceramic coatings, titanium carbide showed the highest improvement in surface hardness, equal to 1817 ± 25 HV, and the lowest coefficient of friction, equal to 0.28 for NbN.