An Improved Process for In-Situ Preparation of Alumina-(Ti, Zr) Borides Composite

Production of superhard Alumina- Zirconium/Titanium diboride in-situ composite and composite powder by self-propagating high temperature synthesis route.

Such composites has applications in wear resistance, corrosion resistance, oxidation resistance, electrical, chemical, metallurgical, cutting tool applications, targets for composite coatings, etc. The produced composite in the present invention may be used either directly or after machining for the required applications. The coating by Sputtering process require a dense material, this process can give required density of these composites, which can be used for composite coatings for wear and corrosion resistance applications.

• This invention relates to an improved process for the fabrication of in-situ synthesis and consolidation of AI2O3- (Ti, Zr) borides composites of approximate 93-98% density to that of theoretical density with controlled grain-growth in the range of less than or the order of 2 micrometer grain size using a dynamic SHS process.
• The processes uses cheaper raw materials compared to conventionally used metal powders.
• The process is fast only few seconds are required for in-situ synthesis and consolidation.
• The Process is energy efficient, No high temperature furnaces are required for the synthesis and sintering only momentarily ignition source is required for starting the self propagating exothermic reaction.
• The obtained product is homogeneous and fine grain, which is required for enhancing strength and toughness.
• The process is economically as well as industrially viable.
• The process can be used to fabricate a range of composite consisting alumina and (Ti, Zr) borides with 92-98% density.
• The obtained product is electrically conducting with resistivity in the range of 300-800 microohm centimeter. Hence can be machined easily by spark erosion process.
• The composite target for nano and hard coatings of Ti-Zr-Al-B-O system by sputtering can be fabricated by this process.