Thermal Spray Conference Presentation In June 2020
Feb 3, 2020
Applying Protective Double Layered Coatings on Magnesium Alloys Using High Pressure Cold Spray Process
M. Daroonparvar, Charles. M. Kay, Rajeev Kumar GuptaResearch and Development Department, ASB Industries. Inc, Barberton, Ohio-44203, United States of America. 2Department of Chemical and Biomilecular Engineering, Corrosion Engineering Program, The University of Akron, Akron, Ohio-44325, United States of America.
Current cold sprayed (N2 as propellant gas) commercially pure (CP)-Al coatings on Mg alloys lack acceptable hardness, wear resistance and are highly susceptible to localized corrosions in chloride containing solutions. Hence, commercially pure α-Ti layer with high passivation propensity (with about 1293.05mV vs. SCE trans-passive potential), hardness and low wear rate was applied on the CP-Al coated Mg alloy. Titanium layer deeply penetrated into Al layer with heavily deformation.
This was accompanied by noticeable densification of softer underneath layer (Al) by hard particles (Ti) with high kinetic energy (hammering effect). Titanium layer raised micro-hardness (HV0.025) from 56.43 (CP-Al coated Mg alloy) to 263.03 for Ti/Al coated Mg alloy. The surface with higher hardness i.e. Ti/Al coating provides lower wear rate followed by Mg bulk and Al coating surfaces, respectively. It should be noted that further studies (long-term corrosion tests) are mandatory to elucidate the effectiveness and corrosion protection performance of cold sprayed double layer coatings on Mg alloys.