Properties and applications of titanium

This paper presents a brief review on titanium alloys, giving especial attention to Ti-6Al-4V. The mechanical and the thermal properties were highlighted, while with regard to application the emphasis was placed to the aerospace, automotive and biomedical fields. The tensile strength of the alloys under concern varies from about 200 to 1400 MPa, but for Ti-6Al-4V the range is from about 900 to 1200 MPa. Generally, the thermal conductivity varies from about 5.5 to 25 W/mK when temperature varies from near room to 200 °C, while for Ti-6Al-4V the values are about 6.6 - 6.8 W/mK at near room temperature, and about 16.0-19.0 W/mK at 800 °C. Aerospace has been the major field of application of titanium materials, being one of the major challenges the development of new alloys with improved strength and higher service temperature. In automotive parts, such alloys are used especially for weight saving, but new alloys with higher service temperature, and new surface treatment to improve wear resistance are needed. New alloys without toxic elements and with elastic modulus similar to the bone need to be developed for biomedical applications.