Oxidation kinetics of metallic inclusions in a composite with an Al2O3-ZrO2 matrix

✍ Scribed by N. A. Mariano; M. A. G. Tommaselli; S. E. Kuri

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 235 KB
• Volume: 36
• Category: Article
• ISSN: 0933-5137
• DOI: 10.1002/mawe.200500877

✦ Synopsis

Many studies have been conducted to obtain toughness in ceramic-ceramic and metal-ceramic composites, using new processing techniques or by addition of metallic inclusions in the ceramic matrix. The oxidation behavior of metallic inclusions, niobium and nickel metallic particles embedded in an Al 2 O 3 -ZrO 2 matrix, was measured through thermogravimetric analysis. In this work oxidation mechanisms were proposed and kinetic parameters defined using a software module for the kinetic analysis of thermal measurements by means of multiple linear or non-linear regression. The morphology of the oxidized surfaces of the samples was examined by using scanning electron microscopy. Oxides were identified by X-ray diffraction. The oxidation kinetics of metallic particles of niobium and nickel are highly complex, for they depend on various factors, i.e., metal's characteristics, processing of the composite, oxygen diffusion through the matrix, grain boundaries, and heating rate applied to the material.