Robotic Microplasma Spraying and Characterization of Zirconium Coatings

A Brief Review of Current Trends in the Additive Manufacturing of Orthopedic Implants with Thermal Plasma-Sprayed Coatings to Improve the Implant Surface Biocompatibility

“…While the functionality and biocompatibility of prostheses are still being improved with more traditional approaches such as surface modification [9][10][11], new technologies are being developed. These primarily include the use of AM to print patient-specific implants [7,12,13], the thermal plasma spray of multilayer biocompatible coatings [14,15], and the automation (robotics) of related technological processes [15][16][17][18].…”

“…This allows for the production of coatings on thin-walled and small-sized parts without deformation or overheating. Additionally, MPS enables the creation of porous coatings on metal endoprostheses using refractory and biocompatible metals (such as Ti, Ta, and Zr) [14][15][16][17]78,84], and their alloys, as well as ceramics such as HA [15,16,19,78,79]. These porous coatings contribute to improved biocompatibility and promote the secondary fixation of the implant by facilitating bone tissue ingrowth into the pores.…”

“…First, the coating experiments for MPS of wire materials such as unalloyed zirconium [17,84,92] and pure titanium [14,15], as well as synthesized HA powder [15,79], were accomplished in a two-level fractional factorial design (2 4−1 ). The following parameters were chosen as variable parameters: current (I, A), plasma gas flow rate (Q, slpm), spraying distance (H, m), and wire or powder flow rate (V w , m/s or V pow , g/min).…”

“…The value of these studies is mainly in obtaining and analyzing data on the characteristics of coatings from biocompatible materials and in applying one research methodology for all materials, which makes it possible to obtain and compare experimental data. MPS parameters and SEM images of zirconium coatings and splats are given in papers [17,84,92]; porosity measurement results for titanium and hydroxyapatite coatings, including SEM images of coatings and particles, are given in papers [14,15]. The regression analysis (the linear model) of the dependency of porosity (%) versus process parameters can be obtained as the regression Equation (1):…”

“…Szala et al (2020) applied a new approach, namely, the fusion of an artificial neural network and genetic algorithm for the selection of atmospheric plasma spray parameters in the design of ceramic coatings with specified hardness, porosity, and superior cavitation erosion resistance [95]. Thus, the selection of MPS parameters applied in papers [14][15][16][17]84] can contribute to further large-scale research on obtaining coatings with controlled porosity by modeling thermal spray process parameters.…”