A TIG surface alloying process was applied to modify the surface of ductile cast iron samples. Using this process, in-situ metal matrix composite (MMC) layers were produced on samples to improve their wear resistance. These layers were made by melting substrate surface and powders as additional material into this melt pool. The efficiency of preheating of the samples to prevent cold cracks during solidification was verified. Moreover, a buffer layer produced in situ to decrease the mismatches between the chemical and physical properties of the materials was also tested. Post-weld heat treatment (PWHT) was used to increase the tribological characteristics of the layers and eliminate adverse effects of the heat-affected zone (HAZ) created by the fusion of the substrate surface. The results showed that, in the samples without preheating, the formation of cold cracks occurred. Additionally, layers produced without a buffer layer showed defects, such as shrinkage and porosity. However, using both preheating and a buffer layer prevented cold cracks, discontinuities, shrinkage, and porosity defects in the layers. Furthermore, PWHT allowed for the transformation of brittle martensite into tempered martensite at the HAZ. MMC layers presented high hardness of up to 1230 HV and wear resistance up to 5.8 times greater compared to the substrate samples without layers.

In this study, titanium and/or copper-based films were deposited onto ZK60 magnesium alloy by reactive sputtering using direct current (DC) and/or radio-frequency (RF) sources. X-ray diffraction and X-ray photoelectron spectroscopy results indicated that the titanium-based films were predominantly composed of TiOₓ (x ≤ 2), indicating the formation of suboxides associated with the incomplete oxidation of Ti during deposition. The ZK60-TiO film, produced under oxygen flow in the chamber and substrate heating at 300 °C, showed a predominance of stoichiometric TiO₂, while the ZK60-Ti metallic film, deposited without oxygen flow in the chamber and without intentional substrate heating, exhibited a predominance of suboxide phases, TiOx (x < 2). Electrochemical tests performed in Ringer's lactate solution demonstrated that the ZK60-TiO film exhibited the best anti-corrosion performance, with higher impedance moduli, more pronounced capacitive behavior, and greater resistance to charge transfer, attributed to its barrier effect promoted by the higher film density provided by the TiO₂ particles. Copper-based films showed low corrosion stability in the electrolyte studied, with evidence of the formation of soluble complexes, resulting in accelerated substrate degradation.