Plasma sprayed copper coatings for improved surface and mechanical properties. (October 2019)

• Record Type: Journal Article
• Authors: Ranjan, Atul; Islam, Aminul; Pathak, Manabendra; Khan, Mohd Kaleem; Keshri, Anup Kumar
• Is Part Of: Vacuum. Volume 168(2019)
• Publication Date: 2019-10
• Subjects: Atmospheric plasma spraying -- Surface morphology -- Mechanical property -- Wettability -- Contact angle hysteresis; Vacuum -- Periodicals; 621.55
• DOI: 10.1016/j.vacuum.2019.108834
• Languages: English
• ISSNs: 0042-207X

Abstract

Abstract: Present draft reports an experimental investigation on surface characterization and mechanical properties of plasma sprayed copper coatings on copper substrate. A comparative analysis of two sample coatings fabricated by two different plasma power of 20 kW and 25 kW has been presented. Surface characteristics, mechanical properties and wetting behaviour of both the sample coatings have been invested. Coatings are characterized with bimodal distributions of both fully and partially melted particles. Coating with 25 kW plasma power possesses higher density and hardness compared to other coating. Typical lamellar structure has been observed in the fractured surface of the coatings. Compared to uncoated substrate, coating surfaces show more surface roughness. However, surface roughness decreases with increase in plasma power. Phase analysis using XRD confirms the formation of cuprous oxide due to oxidation of feedstock copper powder at high temperature during coating process. Formation of cuprous oxide with low surface energy material affects the wetting characteristics of the coated surfaces as compared to the uncoated surface. Average advancing contact angle increases with increase in plasma power and huge contact angle hysteresis has been observed for both the coated surfaces. Both the coatings show parahydrophobic behaviour exhibiting petal effect which helps in better heat transfer at higher heat flux. Highlights: Characterization of plasma sprayed copper coating on copper substrate has been reported. Bimodal distribution of fully and partially melted copper powder has been observed. XRD analysis confirms the formation of cuprous oxide, which affects the surface wettability. Coating surfaces show parahydrophobic behaviour with huge contact angle hysteresis.