Formation and properties of Ti-based Ti–Zr–Cu–Fe–Sn–Si bulk metallic glasses with different (Ti + Zr)/Cu ratios for biomedical application

• Ni- and Be-free Ti-based bulk metallic glasses (BMGs) with high (Ti+Zr)/Cu ratio were developed as promising biomaterials.
• The glassy alloy system exhibits high strength, good bio-corrosion resistance and hydrophilicity.
• The Ti47Zr7.5Cu40Fe2.5Sn2Si1 BMG with high GFA, good mechano- and bio-compatibility is a potential biomaterial as implants.

Ti-based Ti–Zr–Cu–Fe–Sn–Si bulk metallic glasses (BMGs) free from highly toxic elements Ni and Be were developed as promising biomaterials. The influence of (Ti + Zr)/Cu ratio on glass-formation, thermal stability, mechanical properties, bio-corrosion resistance, surface wettability and biocompatibility were investigated. In the present Ti-based BMG system, the Ti47Zr7.5Cu40Fe2.5Sn2Si1 glassy alloy exhibited the highest glass forming ability (GFA) corresponding to the largest supercooled liquid region, and a glassy rod with a critical diameter of 3 mm was prepared by copper-mold casting. The Ti-based BMGs possess high compressive strength of 2014–2185 MPa and microhardness of 606–613 Hv. Young's modulus of the Ti47Zr7.5Cu40Fe2.5Sn2Si1 glassy alloy was about 100 GPa, which is slightly lower than that of Ti–6Al–4V alloy. The Ti47Zr7.5Cu40Fe2.5Sn2Si1 glassy alloy with high GFA exhibited high bio-corrosion resistance, and good surface hydrophilia and cytocompatibility. The mechanisms for glass formation as well as the effect of (Ti + Zr)/Cu ratio on bio-corrosion behavior and biocompatibility are discussed.