Composition dependence of the structure and properties of as-cast Ti-Cr-Co alloys for biomedical applications

The examination of a series of as-cast Ti-Cr-Co alloys was performed with the purpose of obtaining new beta-type Ti-alloys. Experimental results revealed that the alloys, containing 10-20 atomic percent Cr and 5 atomic percent Co, were single beta-phase alloys. They displayed hardness values in the order of 359 to 423 HV, high compressive strength (1620-1990 MPa), high yield strength (1050-1190 MPa) and low elastic modulus (47-72 GPa), which all increased with an increase in the chromium content. The)beta-phase alloys showed very high plastic strain which reduced from 79 to 64 % with an increase in the chromium content. All experimental alloys revealed very good corrosion resistance, according to the E-pit values (1200-1300 mV), which was not significantly influenced by the chemical composition of the alloys. According to the best combination of high strength, low elastic modulus and high plasticity, the new Ti85Cr10Co5 and Ti85Cr15Co5 beta-type Ti-alloys showed a potential for biomedical applications.