Sharpness improvement of surgical blade by means of ZrCuAlAgSi metallic glass and metallic glass thin film coating

Zr-based bulk metallic glasses (BMGs) possess excellent unique properties, such as high mechanical properties, good corrosion resistance, long-term antimicrobial ability, and were considered as an ideal candidate for medical tools. In this study, self-made ZrCuAlAgSi BMG surgical blade and commercial martensitic steel blade with and without metallic glass thin film (MGTF) were carefully examined for their sharpness. The amorphous state of BMG and MGTF were ascertained by X-ray diffraction (XRD) and differential scanning carlorimetry (DSC) analysis. A specially designed indentation-cutting rig was established to evaluate the sharpness of each blade on cutting the soft rubber material. The sharpness was evaluated by the blade sharpness index (BSI) which represents the ratio of external work done by the load to the energy required to initiate a cut or crack inside given materials. Results of sharpness test reveal that both BMG blade and the MGTF coated blade exhibits much lower surface roughness at their tip-edge and smaller BSI values (0.25 and 0.23, respectively) than the commercial blade (∼0.34), which corresponds to 26.5% and 32% improvement on the sharpness, respectively.