Effect of substrate bias voltage on structural and tribological properties of W-Ti-C-N thin films produced by combinational HiPIMS and DCMS co-sputtering

Effect of Substrate Bias Voltage on Microstructure and Mechanical Properties of Cr-Nb-Ti-Zr-N-O Ceramic Thin Films Produced by Reactive Sputtering

“…By increasing the bias voltage (S125 and S200), the crystallinity rises significantly (see XRD and Raman peak intensities and numbers in Figures 1 and 2). This trend was recorded in the other study [33] that worked on the bias voltage variation effect on the structure of multi-component ceramic film. Moreover, the morphology and topology of the coatings change remarkably by increasing the substrate voltage.…”

“…To add to it, it must be mentioned that defects can facilitate crack propagation, delamination and fracture. This is especially evident when there are micro-voids/columnar boundaries in the morphology of the coatings because they have low cohesive energy to propagate cracks [33,49]. To study this feature in samples S50, S125 and S200, Figure 10b shows the predictable trend (higher defect density can cause higher deformation and wear characteristics).…”

“…Hence, the average calculated area of macro-particles for 5 µm scale S50 images (such as the 2D AFM image) is 14%, and its total defect density is 31% (17% from Figure 5a and 14% from Figure 4a). In addition, from AFM results, one can extract surface fractal parameters by graphical software [24,33]. Table 2 summarizes the data of average roughness (Ra), root mean square roughness (Rq), skewness (Sk), kurtosis (Ku) and fractal parameter (D).…”

“…Generally, reactive sputtering is a beneficial process to gain high-quality coatings. To control and design the microstructure of thin films, one can alter the substrate temperature [29,30], reactive gas type or content [31,32], substrate bias voltage [33][34][35][36] and target power [37,38]. Furthermore, it is important to investigate the effect of these parameters on mechanical properties.…”

“…If it is too low, an amorphous with columnar/porous structure is obtained (which is hazardous for tribological properties) [39], and if it is too high, a large grain size is obtained and energy costs can be increased (which is not desirable) [40]. Likewise, the substrate bias voltage and peak power should be fixed at an intermediate value to produce high-energy particles with high deposition rates simultaneously [33][34][35]37]. In addition, it is suggested to set an intermediate level for the nitrogen-to-argon flow rate ratio in order to achieve higher hardness [32,41,42].…”