Titanium and aluminum nitride synthesis via layer by layer LA-CVD I. Shishkovsky a, *, Yu. Morozov b , I. Yadroitsev c , I. Smurov c a Samara State Technical University, Molodogvardeiskaja st. 244, 443110 Samara, Russia b Institute of Structural Macrokinetics and Materials Science, Russian Academy of Sciences, Institutskaya str., 8, Chernogolovka, Moscow Region, 142432, Russia c Ecole Nationale d’Inge ´nieurs de Saint-E ´ tienne (ENISE), DIPI Laboratory, 58 rue Jean Parot, 42023 Saint Etienne, France 1. Introduction The breadth of a range of physical and chemical properties and application fields of titanium and aluminium nitrides (AlN), in last years has stimulated the great interest to methods of their fabrication. Titanium nitride (TiN) is steady against chemical influences, maintains temperature up to 3000 8C and possesses electro conductivity almost twice greater than titanium [1–3]. Aluminum nitride also has such unique properties, as excellent thermal conductivity, high chemical resistance, high melting temperature, wide band-gap and small electron affinity [4–7]. Selective laser sintering/melting (SLS/M) of powder composi- tions is well spread method of the 3D functional tools and fabrication of extremely complex articles in the rapid prototyping and manufacturing technology. It is ideal for producing a wide range of electronic and ‘‘smart’’ micro-electro-mechanical devices. The main problems of direct SLS from powders ready AlN or TiN, are their high melting temperatures up to 2227 8C and 2950 8C, accordingly. This can be overcome by using lower melt material to bind the AlN or TiN articles together. As was remarked [8], the use of pure Al as a binder for AlN results in some curling of layers article. The use of DTM binder (Rapid Steel 2.0 – DTM Co., Austin, Texas, USA) is more preferable, but in any case it needs the post processing. In our studies the possibilities of direct synthesis of TiN and AlN [9,10] under gaseous nitrogen (or ammonia) overpressure so and functional-graded 3D articles from titanium nitride [9] via layer- by-layer SLS were shown. Synthesis of new phases due to a gas transport from the environment had been named as selective area laser deposition vapor infiltration (SALDVI) [3,9,11,13–15]. The objectives of this study were the solid 3D article fabrication via selective laser melting process on the Phenix-100 machine (ENISE, France), which equipped by a high temperature furnace. Optical metallography, SEM, X-ray and EDX analysis were used for study of structure and phase composition of sintered (melted) articles depend on the laser influence regimes. 2. Materials and equipment All reagents were obtained from the French Chemical Market and used as supplied. Titanium powder was the TiGD2 (TLS Technik GmbH & Co.) grade 99.76 wt% Ti; and aluminium powder was Aluminium Grenaille 350TL (Me ´ taux & Chimie) grade 99.6 wt% Al. Titanium and aluminium powders were 25 mm and 32–47 mm grade, correspondently. PM 100 machine (Phenix Systems) has the typical design for SLM equipments [12]. Macrostructures studied by means of OLYMPUS BX60M with a digital camera. Microstructure and elemental analysis of the sintered samples were done by scanning Applied Surface Science 255 (2009) 9847–9850 ARTICLE INFO Article history: Available online 22 April 2009 PACS: 42.62.b 64.70.dj 81.05.Rm 81.20.Ev Keywords: Selective laser melting Selective area laser deposition vapour infiltration Laser assisted CVD (LA-CVD) ABSTRACT The possibility of the layer-by-layer synthesis of 3D parts from nitrides of titanium or aluminum by selective laser sintering/melting is discussed. The relationship between laser processing parameters and structure and phase content of sintered/melted samples are studied by means of optical metallography, X-ray diffraction, scanning electron microscopy and energy dispersive X-ray analysis. Optimal parameters of SLM process for AlN and TiN synthesis are determined. Solid 3D parts containing a TiN phase are produced from Ti powder. Distortion of the crystalline lattice of AlN and TiN phases is observed with the laser energy input. ß 2009 Elsevier B.V. All rights reserved. * Corresponding author. Tel.: +7 846 3344220; fax: +7 846 3355600. E-mail addresses: shiv@fian.smr.ru, shiv@shiv.fian.smr.ru (I. Shishkovsky), morozov@ism.ac.ru (Y. Morozov), smurov@enise.fr (I. Smurov). Contents lists available at ScienceDirect Applied Surface Science journal homepage: www.elsevier.com/locate/apsusc 0169-4332/$ – see front matter ß 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.apsusc.2009.04.104