Low temperature synthesis of nano Ti(C,N) by novel mechanical and thermal activation method

Abstract

This paper presents a novel mechanical and thermal activation assisted carbothermal reduction (CR) method for synthesising Ti(C,N) powder at lower temperatures. Nano Ti(C,N) powder with approximately 30 nm grain size was synthesised by mixing powders of titanium, anatase, and carbon black. The starting powders were first milled for 10 to 40 h under N 2 /Ar atmosphere, and then vacuum heat treated for 1 h at 800 to 10508C. Consequently, nano Ti(C,N) powder with approximately 30 nm grain size was synthesised. X-ray diffraction analysis shows that Ti(C,N) is partially formed during mechanical milling, and the remaining reactants react completely below 10508C. However, when the unmilled starting powders are heat treated at 10508C under N 2 for 1 h, large amounts of reactants remain. Thermogravimetry and differential scanning calorimetry analysis shows that the CR reaction of activated TiO 2 occurs at a lower temperature under N 2 than under Ar or vacuum.

Preparation and characterisation of TiN by microwave-assisted carbothermic reduction–nitridation in air atmosphere

“…Owing to these remarkable properties and extensive applications, it is worth to develop various synthesis ways of TiN powders at low temperature with convenient manipulations. Many synthesis methods of TiN are adopted in literatures including direct nitridation of titanium metal through various techniques [5,[10][11][12][13], self-propagating high temperature synthesis [14], combustion synthesis [15,16], solid state metathesis [17,18], carbothermal reduction of titanium dioxide (TiO 2 ) or ilmenite (FeTiO 3 ) in N 2 atmosphere [19][20][21][22]. Among them, carbothermal reduction-nitridation is deemed as an effective method with the advantages of economy and efficiency.…”

“…Nowadays, hard materials have garnered enormous attention of both fundamental scientists and applied researchers [1-5]. Among them, titanium nitride (TiN) with high hardness (19.6 GPa), dystectic point (2927°C), excellent thermal and electrical conductivity has been commonly utilised in wear-resistance coatings on cutting tools, hot work industries, aircrafts, solar cells and electrocatalysis [69].…”

Effect of short carbon fibre concentration on microstructure and mechanical properties of TiCN-based cermets

“…As an important ceramic tool material, TiCN-based cermets possess not only high hardness, favourable wear resistance, excellent high-temperature oxidation resistance, good chemical and electrochemical stabilities of ceramics but also excellent plasticity similar to cemented carbide, and thus they have been widely utilised in many areas namely aerospace industry, engineering machinery, high-speed cutting, oil and mining industries, and so forth. [1][2][3][4][5][6][7][8][9][10] However, one significant disadvantage for TiCN-based cermets is that their strength and toughness are still not high enough to be used in some industries, especially in elevated-temperature environment restricting its application, when compared with the traditional WC-Co cemented carbide materials.…”