Fabrication and High Temperature Creep Behaviour of Interpenetrated Nickel-Chromium/Alumina Composites
Haeger, A; Schell, KG; Nagel, A; Bucharsky, EC; Oberacker, R; Hoffmann, MJ
ADVANCED ENGINEERING MATERIALS, Band 14, Heft 9, S. 795-801, DOI: 10.1002/adem.201200055
A method to manufacture unique interpenetrating 50?vol% nickelchromium/alumina composites, namely NiCr8020/Al2O3/50pp, is reported. Key process is a high temperature squeeze casting procedure at temperatures above 1500?degrees C used to infiltrate alloy NiCr8020 into porous alumina preforms exhibiting a bimodal pore structure. Microstructure and mechanical properties of this new composite material are presented. Bending creep tests at 1000 and 1150?degrees C are performed. The obtained results are discussed in comparison to a nickel based superalloy. It is shown, that particle preform reinforcement is a promising method to improve creep resistance of nickel based alloys significantly. Due to its outstanding creep resistance, the composite material has a high potential for structural and tribological applications at high temperatures in oxidizing atmospheres.