Abstract
The use of cold spray deposition, coupled with diffusion-driven thermal postprocessing, is considered herein as a surface modification process such that near-surface microstructural, micromechanical, and microchemical property improvements can be procured for cost-effective and common aluminum alloy castings. Since the present work was an exploratory investigation into the realm of cold spray induced, high-pressure diecast aluminum subsurface property development and evolution, as well as surface modification, one significant aim was to formalize a set of fundamental observations for continued consideration of such an approach to achieving premium aluminum alloy properties from cost-effective alternatives. Nickel, copper, and titanium cold spray modified near-surface regions of the cost-effective high-pressure diecast A365 system was considered. Near-surface, subsurface, and surface evolution was documented across each of the three pure metal coatings. The analysis was continued across two postprocessing coating-substrate atomic diffusion inspired heat-treated conditions as well. Using energy-dispersive X-ray spectroscopy, field-emission scanning electron microscopy, optical microscopy, and various insights gleaned from an original contextualization of the relevant cold spray literature, noteworthy results were recorded and discussed herein. When copper feedstock was employed alongside thermal postprocessing, diverse surface-based intermetallic compounds formed alongside exotic diffusion zones and severely oxidized regions, thus eliminating thermally activated copper cold-sprayed consolidations from future work too. However, both nickel and titanium cold spray surface modification processing demonstrated potential and promise if correct processing stages were performed directly and chronologically. Consequently, a platform is presented for further research on cold sprayed surface microstructural and property modification of cost-effective alloyed aluminum castings.
Highlights
Cold gas dynamic spray (CGDS), or less formally, cold spray, is a solid-state materials consolidation and processing technology that utilizes particulate feedstock that is transported via a heated carrier gas stream until exiting a de Laval nozzle and supersonically impacting a substrate [1]
We have substantiated the identification of Ti and Ni CGDS deposition as a promising surface modification technique for cost-effective near-surface property enhancement of A365 aluminum alloy high-pressure diecast (HPDC) materials
Cu CGDS, the third CGDS deposition feedstock considered during this work, was eliminated as a prospective coating material for the present purposes since thermally mediated Cu CGDS atomic diffusion into the HPDC A365 subsurface region resulted in deleterious microstructural and property evolution
Summary
Cold gas dynamic spray (CGDS), or less formally, cold spray, is a solid-state materials consolidation and processing technology that utilizes particulate feedstock that is transported via a heated carrier gas stream until exiting a de Laval nozzle and supersonically impacting a substrate [1]. Successful CGDS processing and materials consolidation depend upon particle-substrate and particle-particle metallurgical and mechanical bonding. CGDS processing parameters vary from the nozzle type to the selection of powder composition and gas source. Feedstock powder for CGDS processing typically has a diameter range from approximately 5 to 100 μm. These particles generally achieve velocities between 300 and 1200 m/s
Sign-in/Register to view highlights & summary 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.
