Effect of bias voltage on the erosion performance of TiAlSiN coatings on TC6 substrate by high power impulse magnetron sputtering

• Published in: Surface & coatings technology 2024-02, Vol.477, p.130263, Article 130263
• Main Authors: Hua, Li, Liuhe, Li, Xiaoting, Wang, Guodong, Li, Duoduo, Li, Yang, Luo, Ling, Tang, Mingyue, Han
• Format: Article
• Language: English
• Subjects: Bias voltage; Erosion; Failure mechanism; HiPIMS; TiAlSiN
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2023.130263

TiAlSiN coatings were deposited on TC6 substrates by high power impulse magnetron sputtering at various bias voltages for the improvement of titanium alloy anti-sand erosion performance. The effect of bias voltage on the composition, microstructure and mechanical properties were investigated by X-ray photoelectron spectroscopy, X-ray diffractometer, transmission electron microscopy, scanning electron microscopy, Rockwell-C indentation, scratch testing and nano nanoindentation. The erosion performance was evaluated at the impingent angles of 30° and 90° respectively in a sand blasting tester. With the application and increase in bias voltage, the discharge current increases from ∼87 A to ∼210 A. The coatings exhibit face center cubic structure, mainly composed of the (Ti,Al)N nanocrystallites and Si3N4 matrix. The preferred orientation shifts from (200) to (220) in the range of 0∼−150 V, but goes back to (200) at −200 V. The surface nodular defects and deposition rate are gradually reduced, yet the sectional structure becomes much denser. The residual stress is compressive and continually grows, whereas the adhesion strength, hardness (H), Young's modulus (E) and H/E ratio gradually increase before decreasing, arriving at maximum values of ∼68 N, ∼37.53 GPa, ∼339.9 GPa and 0.11 respectively at −150 V. The erosion resistance of the TiAlSiN coatings is consistent with these mechanical changes at various bias voltages and is also optimal at −150 V, which is ∼14 times that of TC6 substrate. The failure mechanism comes from coating brittleness nature, fractured chips and microcracks, regardless sand erosion angles, yet the driving forces are different. •The erosion resistance of TiAlSiN coatings is consistent of the variation of their mechanical properties with bias voltages.•The composite TiAlSiN coatings with optimal erosion resistance is deposited at −150 V in HiPIMS.•Surface nodule defects seriously deteriorate the erosion damage.•The erosion mechanisms of coatings are from their brittle nature, fractured chips and microcracks, regardless sand erosion angles.•The microcracks are more apt to appear at the hard coating with low toughness.