Effect of Ni addition on the densification of TiC: A comparative study of conventional and microwave sintering

Autor: Ashwath Aravindhan, Nivedhita Vasudevan, Nuzhet Nihaar Nasir Ahamed, Pavithra B, Balasivanandha Prabu Shanmugavel
Rok vydání: 2020
Předmět:
Zdroj: International Journal of Refractory Metals and Hard Materials. 87:105165
ISSN: 0263-4368
DOI: 10.1016/j.ijrmhm.2019.105165
Popis: This study deals with the effect of conventional sintering and microwave sintering on the densification kinetics of Titanium Carbide (TiC) in the presence of Ni (1, 1.5, 2 wt%). TiC compacts were obtained after uniaxial pressing of powders synthesised by ball milling of Titanium and Carbon and sintering was done in the presence of Nickel. The samples prepared were subjected to conventional as well as microwave sintering. The XRD and SEM analysis were used for a study of the reaction of Ti and C powders upon addition of Ni, which reduced the sintering temperature to 1200 °C. The densification of TiC powders was due to the Ti-Ni eutectic system, the liquid phase formed at this temperature assisting the sintering process. The SEM images revealed the flake like structure of TiC in which the carbon diffused into Ti upon the addition of Ni, thereby supporting enhanced mass transfer. The XRD pattern showed the presence of Titanium Oxide (TiO2) along with TiC which resulted in non-uniform distribution of hardness. Maximum hardness was achieved in the conventional sintered compacts which gradually increased with increase in Ni addition. The presence of the oxide phase and the formation of micro cracks resulted in non-uniform hardness for microwave sintered compacts. The maximum hardness of conventional sintered compact (375 HLD) was nearly 1.5 times more than the maximum hardness of the microwave sintered compact (250 HLD). The density of the microwave sintered compact was found to be higher by 8% than with the conventionally sintered compact.
Databáze: OpenAIRE