Fabrication and microstrain evolution of Al-TiB2 composite coating by cold spray deposition

Chen, H.; Pala, Zdenek; Hussain, T.; McCartney, D.G.

Abstract

This paper investigates the microstructure evolution of Al-TiB2 coatings prepared by cold spraying. In situ Al-TiB2 composite powders containing uniformly distributed titanium diboride (TiB2) particles with a size range of 5 to 100 nm in the Al matrix and Al/Al-TiB2 blended powders were used as the cold spray feedstock for coating fabrication on aluminium alloy substrates. The microstructures of the feedstock powders and as-deposited coatings were characterised using scanning electron microscopy with energy dispersive X-ray (EDX) analysis and X-ray diffraction (XRD). Al/Al-TiB2 blended powder coatings, compromising closely packed powder particles, were sprayed to an approximate thickness of 500 μm. Al-TiB2 composite coatings (approximately 50 μm thick) were obtained retaining the microstructure of the composite powders being sprayed and no evidence of detrimental phase transformation was found. However, micro-cracks were found to exist in the Al-TiB2 coating due to the hardly deformable powder particles. Little or no microstrain was revealed in the as-sprayed Al-TiB2 coating, indicating that annealing may have occurred due to the localised adiabatic heating during the spraying process. It is demonstrated that it is possible to fabricate the Al-TiB2 composite coating by cold spray deposition but further improvements to eliminate coating cracking are required.

Citation

Chen, H., Pala, Z., Hussain, T., & McCartney, D. (in press). Fabrication and microstrain evolution of Al-TiB2 composite coating by cold spray deposition. Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications, https://doi.org/10.1177/1464420717690559

• Journal Article Type: Article
• Acceptance Date: Jan 4, 2017
• Online Publication Date: Jan 29, 2017
• Deposit Date: Feb 3, 2017
• Publicly Available Date: Feb 3, 2017
• Journal: Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications
• Print ISSN: 1464-4207
• Electronic ISSN: 2041-3076
• Publisher: SAGE Publications
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1177/1464420717690559
• Keywords: Aluminium matrix composite, cold spray, Al-TiB2, cracking, microstrain
• Public URL: https://nottingham-repository.worktribe.com/output/838713
• Publisher URL: http://journals.sagepub.com/doi/10.1177/1464420717690559
• Contract Date: Feb 3, 2017