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 degrees 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.