High energy grinding in Al2O3-NiCrAl composite powders synthesis

• Grant number: 06/06011-0
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): December 01, 2006
• Effective date (End): August 31, 2007
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal researcher: Jose Deodoro Trani Capocchi
• Grantee: Danielle Goya Simões
• Home Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The influence of high-energy milling in the synthesis of Al2O3-NiCrAl composites will be studied with the milling of NiO, Cr and Al powders. Metallic aluminium will be used with 10% excess of aluminium on stoichiometric relation. The high-energy millings will be performed using steel jar and balls in a SPEX vibratory mill. The ocurrence of reactions will be analysed by a K-type thermopar with a datalogger, which registers possible abrupt temperature elevations. Those kind of abrupt elevations indicates Self-propagating High-temperature Synthesis (SHS) reactions. The ball-to-powder weight ratio will be 7:1. Resulting products will be analysed by X-Ray diffraction, scanning electron microscopy and DTA/DSC analyses. If the millings do not succed in the Al2O3-NiCrAl composites synthesis, the samples of milling products will be thermically treated.