Cyclic Nanoindentation and Finite Element Analysis of Ti/TiN and CrN Nanocoatings on Zr-Based Metallic Glasses Mechanical Performance

Abstract

Cyclic depth-sensing nanoindentation tests are carried out to unravel the effect of monolithic and multilayer thin coatings on loadbearing capacity and stress distribution in the coating-Zr-based metallic glass systems. Thin films of TiN, CrN, and Ti/TiN multilayer, having thickness of 300 nm, are deposited on Zr 60 Ni 10 Cu 20 Al 10 and Zr 50 Cu 40 Al 10 metallic glasses by RF sputtering technique. Strain softening occurs over several cycles in Zr-based metallic glasses, CrN, and TiN films as evidenced by a disparity between the unloading and reloading sequences. However, the cyclic nanoindentation of Ti/TiN multilayer coating results in a hysteresis loop in the load-depth profiles, and this event depends on the number of cycles and the loading rates. AFM and SEM characterization of remnant imprints revealed microcraks and crack-like shear bands in nanocoatings and Zr-based metallic glasses, respectively. Based on shear-fracture driven plastic flow of the coatings, a modified cavity model is used to determine the shear stress evolution as a function of penetration depth. The finite-element simulations predicted the stress distribution beneath the indenter and are well consistent with the evolving trend of shear stress obtained from experiments.

Fatigue behaviour and mechanical properties of PVD CrSiN coating using cyclic nanoindentation

“…This phenomenon of strain hardening producing hysteresis loops (see Figure 3) was confirmed by the results presented in Figure 4. This finding was obtained by dislocation–microstructure interactions [20]. Beyond 30 cycles, the maximum penetration depth did not exceed 0.8 µm and a decrease in hardness values was noticed due to the fatigue damage of coating.…”

“…Hysteresis loops are produced, which signifies that the deformation resistance of CrSiN coating becomes greater during the reloading path compared to the unloading one. The hysteresis loops, produced after cyclic nanoindentation test on PVD thin film, were found by Tekaya et al [20,21]. Figure 4 represents the variation of hardness with the penetration depth in the incremental cyclic loading mode at 5 and 50 cycles.…”

Crack Propagation in As-Extruded and Heat-Treated Mg-Dy-Nd-Zn-Zr Alloy Explained by the Effect of LPSO Structures and Their Micro- and Nanohardness

“…The significant load dependence of the hardness values of the LPSO lamellae region with narrow distances can be explained by the layered structure. The layers seen in the micrographs will not be cut at an exact 90-degree angle, which means that deeper measured areas will contain more or less Dy-, Nd-and Zn-enriched layers, leading to lower and higher values of one single multi-cycle indent, so-called depth-sensing nanoindentation, which is often found in multilayered coatings or functionally graded materials [55,56].…”

Identification of the elastic-plastic properties of CrN coating on elastic-plastic substrate by nanoindentation using finite element method-reverse algorithm

“…For the CrN coating, several studies have evaluated its Young's modulus through an analytical approach (Oliver-Pharr method) or by [41] 2 DC-PVD** cemented carbide 19 [42] 1.3 RF-PVD 2 silicon 16 [43] 1 DC-PVD silicon 13 [44] 0.3 RF-PVD metallic glass 12 [45] 0.6 DC-PVD silicon 10 [46] 0.3 RF-PVD metallic glass 8.5 [47] 2 DC-PVD stainless steel Microhardness test 5 [47] 2 DC-PVD stainless steel 3-22 [48] 4-5 DC-PVD stainless steel E (GPa) 437 [41] 2 DC-PVD cemented carbide Olivar and Phar (nanoindentation tests) 360 [40] 0.8 DC-PVD stainless steel 235 [45] 0.6 DC-PVD silicon 170 [43] 1 DC-PVD silicon 160 [44] 0.3 RF-PVD metallic glass 100 [46] 0. finite element modeling and found values between 100 and 437 GPa (Table 3). Based on (JH) model results (Table 2), Young's modulus of the CrN coating varies between 67 and 205 GPa and hence, the bound constraints have been defined between 50 and 240 GPa.…”