Abstract
Abstract Thermal spraying may be a promising approach for the deposition of NiAl-Al2O3 composite coatings. To understand the intrinsic mechanical property of NiAl-Al2O3 composite, dense NiAl-Al2O3 composites were prepared by plasma activated sintering using the ball milled Ni/Al- Al2O3 composite powders contain both micro-sized Al2O3 strengthening particles and submicron-sized Al2O3 dispersoids homogeneously distributed in the NiAl matrix phase. The angular morphology of the Al2O3 particles in composite powder was changed to spherical or near spherical morphology after plasma activated sintering. Compared to the NiAl-Al2O3 composites with low Al2O3 content, NiAl- 60vol.%Al2O3 composite consisted of less fine submicron-sized Al2O3 dispersoids. Melting induced mechanism was proposed to explain the spheroidization and the change of Al2O3 particle size distribution. The hardness of the NiAl-Al2O3 composites with both micro-sized Al2O3 strengthening particles and submicron-sized Al2O3 dispersoids increased with the increase of Al2O3 content. The relation was employed to theoretically estimate the hardness using volume fractions of components and corresponding hardness. The estimated hardness was compared with the observed ones. It was found that bimodal sized particles reinforcement results in a higher hardness than the theoretical value, which could be attributed to the dispersion hardening effect.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
