Optimization of the Electrophoretic Deposition Parameters and Mechanism of Formation of Ag-TiO2 Nanocoatings on a NiTi Shape Memory Alloy: Part I

This paper reports research findings on the functionalization of NiTi shape memory alloy through the electrophoretic deposition of innovative complex layers comprising a silver-rutile (Ag-TiO2) nanocomposite. A colloidal suspension of a chemically synthesized Ag-TiO2 nanosystem prepared with a 59.4 ± 0.9 mV Zeta potential for anaphoretic deposition. Employing a design of experiment method (DoE), the optimal parameters for uniform coating depositions were identified as 40 V/3 min. Dilatometric tests and high-temperature microscopy determined that the deposited layers’ heat treatment temperature should not exceed 800 °C. Raman spectrometry and scanning electron microscopy (SEM) provided comprehensive structural and morphological insights into the resulting continuous and crack-free layer. The article extensively explores the impact of annealing on structural changes within the layer, proposing mechanisms for its formation. The findings affirm the feasibility of creating a highly reactive layer on the NiTi alloy, holding potential significance in implantation medicine.