A study of TaxC1−x coatings deposited on biomedical 316L stainless steel by radio-frequency magnetron sputtering

Abstract In this paper, Ta x C 1 −x coatings were deposited on 316L stainless steel (316L SS) by radio-frequency (RF) magnetron sputtering at various substrate temperatures ( T s ) in order to improve its corrosion resistance and hemocompatibility. XRD results indicated that T s could significantly change the microstructure of Ta x C 1 −x coatings. When T s was x C 1 −x coatings were in amorphous condition, whereas when T s was ≥150 °C, TaC phase was formed, exhibiting in the form of particulates with the crystallite sizes of about 15–25 nm ( T s = 300 °C). Atomic force microscope (AFM) results showed that with the increase of T s , the root-mean-square (RMS) values of the Ta x C 1 −x coatings decreased. The nano-indentation experiments indicated that the Ta x C 1 −x coating deposited at 300 °C had a higher hardness and modulus. The scratch test results demonstrated that Ta x C 1 −x coatings deposited above 150 °C exhibited good adhesion performance. Tribology tests results demonstrated that Ta x C 1 −x coatings exhibited excellent wear resistance. The results of potentiodynamic polarization showed that the corrosion resistance of the 316L SS was improved significantly because of the deposited Ta x C 1 −x coatings. The platelet adhesion test results indicated that the Ta x C 1 −x coatings deposited at T s of 150 °C and 300 °C possessed better hemocompatibility than the coating deposited at T s of 25 °C. Additionally, the hemocompatibility of the Ta x C 1 −x coating on the 316L SS was found to be influenced by its surface roughness, hydrophilicity and the surface energy.