Ni-assisted synthesis and densification processes of TiC based materials
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Date
2025-01-30
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Publisher
National Higher School of Technology and Engineering. Annaba
Abstract
This study investigates the synthesis and densification of titanium carbide based materials using two distinct approaches. The first incorporates mechanically activated NiO/Al powder into a Ti+C mixture, while the second directly adds nickel powder to the Ti+C mixture. Self-propagating high-temperature synthesis and hot pressing were employed for material synthesis. To enhance densification and microstructural properties, hot-pressed samples underwent heat treatment at 1450°C. Optimizing the NiO/Al milling parameters led to the most refined mixture using a ball-to-powder ratio of 42:1, a milling speed of 200 rpm, and a duration of 1 hour. The introduction of mechanically activated NiO/Al into the Ti-C system significantly accelerated the combustion synthesis process, leading to the formation of TiC, hot Ni, and Al₂O₃. X-ray diffraction analysis confirmed that the dominant phases formed during hot pressing were TiC, nickel, and alumina, alongside intermetallic phases such as Ti₂Ni and NiTi. Microstructural analysis showed that TiC without additives had high porosity, while NiO/Al incorporation resulted in a denser structure with smaller TiC particles.
For Ti-C-Ni samples, XRD analysis confirmed the formation of TiC along with intermetallic phases such as Ti₂Ni, TiNi, and Ni₃C across both synthesis routes. Comparative analysis demonstrated that TiC synthesized with the mechanically activated NiO/Al mixture exhibited superior performance compared to TiC obtained through direct nickel addition. Moreover, Electron Probe Microanalysis validated the XRD findings for hot-pressed samples, while Scanning Electron Microscopy highlighted nickel's presence at TiC grain boundaries. The tribological evaluation further indicated that samples with higher binder content exhibited increased friction coefficients, emphasizing the correlation between binder concentration and wear resistance.