Improvement of solid particle erosion and corrosion resistance using TiAlSiN/Cr multilayer coatings

The TiAlSiN/Cr multilayer coatings with different thicknesses of chromium (Cr) layers were designed and prepared by high power impulse magnetron sputtering (HiPIMS) and direct current magnetron sputtering (DCMS) for the improvement of their solid particle erosion and corrosion resistance. The structure-property relationship was investigated by the systematic characterization of the microstructure, hardness, Young's modulus, toughness, solid particle erosion resistance, and corrosion properties of those coatings. The results reveal that the TiAlSiN layers consisted of the TiN crystalline phase and amorphous phase. As the Cr layers thickness increased, the grain growth of the Cr layers was columnar with a strong Cr (110)-preferred orientation. Compared with the TiAlSiN coating, the TiAlSiN/Cr multilayer coatings showed significantly improved toughness and corrosion performance. The toughness, H/E ratio, erosion resistance at impact angle of 90°, and corrosion resistance of the TiAlSiN/Cr multilayer coatings firstly increased when the Cr layer thickness increased up to 21 nm, before decreasing with a further increase of Cr layer thickness. Our results show that the TiAlSiN/Cr multilayer coatings with the Cr layer thickness of 21 nm exhibit enhanced toughness, excellent erosion resistance, and corrosion resistance together with high hardness.