Microstructure, Micro-Indentation, and Scratch Behavior of Cr Films Prepared on Al alloys by Using Magnetron Sputtering

Abstract

In this study, closed-field unbalanced magnetron sputtering (CFUMS) was employed to deposit pure Cr films on soft substrate of 2024 Al alloy. The effects of deposition powers and biases on the microstructures and mechanical performance of Cr films were systematically investigated by using X-ray diffraction (XRD), scanning electron microscope (SEM), micro-indentation and scratch test. Results showed that all the Cr films had a strong (110) preferred orientation and anisotropic surface morphology with columnar structures. The size of Cr particles was in the range of 50–350 nm, increasing with larger target power and higher biases. The hardness of Cr films was between 3.3 and 4.8 GPa, which was much higher than the Al alloy substrate (1.44 GPa). The Young’s modulus of Cr film could reach a maximum value of 169 GPa at 2.0 kW/70 V. The critical load increased when increasing the power but decreased with higher bias, achieving a maximum value of 53.83 N at 2.0 kW/10 V. The adhesive failure mechanism of Cr film was mainly attributed to the plastic deformation of softer Al substrate.

Elasto-Plastic Design of Ultrathin Interlayer for Enhancing Strain Tolerance of Flexible Electronics

“…Sample i (Cu/PI) serves as a reference, and its ε̅ value is 1.00. Poly­(methyl methacrylate) (PMMA) and Cr were chosen as interlayers for Sample ii (Cu/PMMA/PI) and Sample iii (Cu/Cr/PI), respectively, because they are widely used as interfacial materials in many electronic devices yet exhibit significant differences in the elasto-plastic properties. − PMMA represents a soft ( E = 4.2 ± 0.8 GPa) yet elastic interlayer (ε Y = 3.4%), while Cr represents a stiff ( E = 265 ± 15 GPa) yet brittle interlayer (ε Y = 0.9%). The ε̅ values of Samples ii and iii are 0.97 and 1.01, respectively.…”

Tribological Properties of TiN Coating on Cotton Picker Spindle

“…At present, PVD technology is one of the most effective technologies for surface modification in surface engineering, and it is also one of the most promising alternative processes for chromium plating [16,17]. The coatings prepared by PVD technology have characteristics of high hardness, good wear resistance, low friction coefficient, dense tissue structure, and strong bonding with the substrate [18,19]. Besides, the prepared coatings have low surface roughness and generally do not require secondary polishing treatment, providing an ideal solution for small shaped parts that are difficult to polish.…”