Microstructure and Mechanical Properties of Low-Pressure Cold-Sprayed (LPCS) Coatings

• Published in: Journal of thermal spray technology Vol. 17; no. 5-6; pp. 721 - 727
• Main Authors: Koivuluoto, Heli, Lagerbom, Juha, Kylmälahti, Mikko, Vuoristo, Petri
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.12.2008; Springer Nature B.V
• Subjects: Analytical Chemistry; Characterization and Evaluation of Materials; Chemistry and Materials Science; Coatings; Copper; Corrosion; Corrosion and Coatings; Machines; Manufacturing; Materials Science; Mechanical properties; Microstructure; Peer Reviewed; Porosity; Processes; Scanning electron microscopy; Sprayers; Spraying; Sprays; Surfaces and Interfaces; Thin Films; Tribology; Zinc; nickel; copper; microstructure; low-pressure cold spraying; zinc; mechanical properties
• ISSN: 1059-9630; 1544-1016
• DOI: 10.1007/s11666-008-9245-6

In low-pressure cold spraying, compressed air is used as a process gas. The most important process parameters are temperature and pressure. In the Low-Pressure Cold Spraying (LPCS) system in this study, the maximum preheating temperature is 650 °C and pressure is 9 bar. Powders used in LPCS process contain alumina with metallic powders; therefore LPCS is the method to spray soft metallic coatings with ceramic hard phase for different application areas, e.g., thick coatings and coatings for electrical and thermal conduction and corrosion protection applications. The aim of this study was to investigate microstructure, denseness, and mechanical properties of LPCS Cu, Ni, and Zn coatings. LPCS coatings seemed to be dense according to Scanning Electron Microscope (SEM) studies but corrosion tests were needed to identify the existence of porosity. Through-porosity was observed in structures of the LPCS coatings. Bond strengths of LPCS Cu and Zn coatings were found to be 20-30 MPa, and hardness was high indicating reinforcement and work hardening.