Engineering Commons^™

Development And Characterization Of The Oxidation Behavior Of Various High Temperature Niobium Based Alloys, Benedict Isabel Portillo

Open Access Theses & Dissertations

The oxidation response of various niobium based refractory alloys from the Nb-Mo-Si-B-X alloy system has been examined at temperatures between 700 and 1400°C in air. The development of these alloys was part of an ongoing effort to develop and discover a new materials system capable of replacing nickel based super alloys. Additions of titanium were found to provide limited oxidation resistance. A discontinuous layer of TiO2 was observed to from at temperatures above 1100°C. Alloys containing titanium additions were observed to suffer from pest oxidation at low and intermediate temperatures due to the development of Nb2O5. Poor oxidation resistance at …

High Temperature Oxidation Behavior Of Nb-20si-20cr Alloys With Hafnium Additions, Alma Rosa Vazquez

Open Access Theses & Dissertations

Advances in aircraft and gas turbine engine technology have steadily increased the operating temperatures, and even the state of the art materials can not meet the requirements for the new challenges. Efforts are under way to study the possibility of substituting nickel-based alloys with niobium-based alloys that offer higher melting points and excellent mechanical properties. Notwithstanding these good properties, the utilization of Nb-based alloys is limited since oxidation resistant is still a serious problem. Therefore understanding the corrosion behavior of Nb-based alloys is a crucial step to enhancing oxidation resistance.

The oxidation behavior of two alloys from the Nb-Si-Cr system …