Phenom prox scanning electron microscope

The FeCoCrNi and FeCoCrNiMo_0.2 high-entropy alloy coatings were cut into 10 mm × 10 mm × 8 mm samples, which were ground with 240 #, 600 #, 800 #, 1000 # and 1200 # sandpapers, respectively, and finally polished. The phase identification of the samples was carried out by an AL-2700B X-ray diffractometer (Dandong Aolong Radiative Instrument Co., Ltd., Dandong, China). The test parameters are as follows: the target is Cu, the scanning range (2θ) is 10°~90°, the scanning speed is 5°/min, the tube voltage is 40 kV and the tube current is 30 mA. After etched with aqua regia solution, the cross-sectional morphology and chemical composition of the coatings were analyzed by a Phenom proX scanning electron microscope (Phenom-World, Eindhoven, The Netherlands) and energy dispersive spectrometer (EDS).

Before starting with SEM observation, a Desk Sputter Coater (Phenom-World B.V., Eindhoven, The Netherlands) was used to sputter the samples with gold (150 A).
A Phenom ProX scanning electron microscope (Phenom-World B.V., The Netherlands) was used to characterize all samples at microscale and to visualize the biofilm formation on the discs.

Glass slides (Menzel Glaser, Braunschweig, Germany) (26 mm × 76 mm × 1 mm) were used as the donor substrate, on the surface of which Ti was deposited by magnetron sputtering using a VSE-PDV-DESK-PRO installation (OOO Vacuum Systems and Electronics, Novosibirsk, Russia). The film surface was studied by atomic force microscopy on a Solver Pro M complex (ZAO Nanotechnology MDT, Moscow, Russia) in order to determine the thickness of the Ti film, which was 50 ± 10 nm.
Immediately prior to laser transfer, a layer of empty gel or gel mixed with yeast was deposited on the surface of the Ti film of the donor substrate (200-μm thick). The gel was an aqueous solution of 2% hyaluronic acid (M_w = 70 kDa, Contipro Pharma, Dolní Dobrouč, Czech Republic).
Opposite the donor substrate with the gel, a 12-well plate (Costar Corning, Corning, NY, USA) was placed and fixed on an automated moving platform. For visual control of the process of formation and the transfer of the gel jets and drops, a Fastcam SA-3 high-speed camera (Photron, Tokyo, Japan) with frontal illumination from a continuous laser with a wavelength of 630 nm was used. After laser exposure, the Ti films were examined using a PHENOM ProX scanning electron microscope (Phenom-World, Eindhoven, The Netherlands) and an HRM-300 Series optical 3D microscope (Huvitz, Anyang-si, Gyeonggi-do, Korea).

The tensile specimens were immersed in disinfectant until saturation. Methylene blue was added in the solution for evaluating the fluid penetration depth by observing the coloring of the fracture surfaces. Specimens were tested using an Instron 8872 Universal Test Machine (Instron Inc., Kawasaki, Japan) equipped with a load cell of 25 kN. The testing speed was set at a rate of 1 mm/min and the extensometer gauge length was 25 mm.
Phenom ProX scanning electron microscope (SEM) (Phenom World, Eindhoven, The Netherlands) was used for investigating if the specimens fracture surfaces show any specific features which might be caused by the disinfectant action.