773 AVILA et al : SYNTHESIS OF ALUMINUM TITANIUM CARBONITRIDE BY MECHANICAL ALLOYING Journal of Scientific & Industrial Research Vol. 69, October 2010, pp. 773-776 *Autor for correspondence E-mail: hjsuarez@uao.edu.co Synthesis and characterization of aluminum titanium carbonitride TiAlCN via mechanical alloying J A Avila 1,3 , H E Jaramillo 1,2,4 *, N A de Sanchez 1,2,4 and H Sánchez Sthepa 3,4 1 Grupo Ciencia e Ingeniería de Materiales, 2 Departamento de Energética y Mecánica, Universidad Autónoma de Occidente 3 Escuela de Materiales, Universidad del Valle, 4 Centro de Excelencia de Nuevos Materiales, Cali-Colombia Received 21 April 2010; revised 29 July 2010; accepted 30 July 2010 This study presents synthesis of titanium aluminum carbonitrides alloy (TiAlCN) by mechanical alloying in Attritor ball mill from elemental powders of titanium, aluminum and graphite in nitrogen atmosphere. TiAlCN was characterized by SEM, XRD, DSC and FTIR techniques. XRD showed presence of titanium aluminum nitride, aluminum nitride, titanium carbide and titanium aluminum carbon nitride, while SEM showed existence of micro and nano particles with high agglomeration. Energy- dispersive spectroscopy (EDS) analysis shows a homogeneous distribution of elements, and mapping analysis from X-rays confirms distribution of elements. Keywords: Carbides, Elemental powders, Mechanical alloying, Nitrides, Titanium aluminum carbonitrides alloy Introduction Development of Ti-Al-N ternary alloy gives an increase in hardness and oxidation resistance in comparison with binary alloy TiN 1 . Quaternary alloys type, titanium aluminum carbonitride titanium (Ti-Al-N-C) has been produced by pulsed laser deposition technique 2-3 , magnetron sputtering technique 6 , and chemical depositions techniques 4 . Titanium aluminum carbonitrides alloy (TiAlCN) hard coating shows high wear and erosion resistance, under high cutting velocity and without lubrication 6 . This study presents synthesis by mechanical alloying and characterization of powder alloy TiAlCN as target to obtain hard coatings. Experimental Section TiAlCN powder (Ti, 55.1; Al, 31.0; and C, 13.9%) was obtained by mechanical alloying in a ball milling atritor of vertical impeller 6 . A stainless steel vial and various Cr steel balls (diam, 6-8 mm) were used. Elemental powder contained: pure Ti (particle size, 150 μm), 99.7 wt%; Al (particle size, < 200 μm), 99.95 wt%; and C (particle size, <45 μm), 99.99 wt%. Mill container air was evacuated using a vacuum pump and then filled with nitrogen gas. Mass balls and powder ratio was 70:1, with 500 rpm constant rotational velocity for 140 h. Compaction process was carried out for specimen 1 with 70 h milling, and specimen 2 with 140 h milling using a universal compression machine, which has a 2000 KN loud cell and a compacting matrix that allows obtaining targets (diam, 1.2 cm). Powder material was compacted (as specimens 1 and 2 of 1 g each), by applied pressure (800 MPa), and target did not present visible defects and was easily ejected from die. Sintering was realized in Nabertherm furnace model LHT 02/1. Specimen 1 was sintered at 1000°C for 1 h with a heating rate of 5°C/min, and specimen 2 at 1400°C for 2 h with a heating rate of 10°C/min. Sintering at 1400°C target showed cracks in bulk in many pieces. Sintering at 1000°C target showed a light delamination, indicating phase transformation between 25-1000°C, after having used differential calorimetry scanning (DSC) to corroborate. X-Ray diffraction analyses (XRD) was carried out in a Panalytical reference X’Pert PRO MPD with Cu ceramic and solid state detector reference PixCel. Microstructure of milled powder, Energy-dispersive spectroscopy (EDS) and mapping of elements was studied in a SEM JEOL JSM 6490LV Scanning Electron Microscope (SEM). Samples transition temperatures were measured by a TA Instruments SDT Q600 Differential Scanning Calorimetry (DSC) Analyzer. Powders were heated to1000°C at a rate of 10°C/min, and Fourier Transform Infrared Spectroscopy