LAUSR

Abstract The effect of carbon addition on the high-temperature tensile properties and microstructure of Ti-43Al-6Nb-1Mo-1Cr alloys has been studied in this paper. 0.5 at.% C could increase both the ultimate tensile strength(UTS) and elongation of the alloys, as 643.85 ± 13.06 MPa and 7.07 ± 1.02% at 800 °C, 540.02 ± 4.29 MPa and 23.55 ± 0.58% at 850 °C, 389.82 ± 10.24 MPa and 40.5 ± 0.41% at 900 °C. With carbon content increasing from 0.5 at.% to 1.0 at.%, the UTS were increased while the elongations were reduced dramatically at high temperatures. 1.0 at.% carbon addition could also stabilize the UTS in the range of 600–800  MPa at 800–900 °C. Additionally, three types of strengthening mechanism and two types of toughening mechanism caused by carbon addition are discussed and concluded.