Investigation of Wear and Corrosion Protection of AlSi20 Coatings Produced by Plasma Spraying and Laser Cladding on AZ31B

摘要

Magnesium and magnesium alloys are the lightest structural materials with an approximate density of 1.7 g/cm~2 (density of aluminum ～2.7 g/cm~2). Due to poor corrosion and wear resistance properties, they need to be coated for usage in service conditions under corrosive and tribological loads. AlSi20 was found to be a suitable coating material to improve the wear and corrosion protection properties of magnesium alloys. Within this work, AlSi20 coatings were applied by plasma spraying, laser cladding, and a combination of both processes. First, the coatings are characterized by their microhardness and residual stresses formed within the coating during the different coating processes. Then, these coatings were investigated regarding corrosion resistance in 3.5% sodium chloride solution in a three-electrode setup to obtain electrochemical corrosion characteristics. Abrasive wear was investigated using a pin-on-disk tribometer and the abrasion rate was calculated. Resistance against shock loads was tested by applying a cyclic load at 50 Hz to investigate the resistance against impact stresses.