Abnormal acceleration of creep deformation rate above 700°C in the orthorhombic based Ti–22Al–27Nb alloy

Nano-mechanical characterization of plasma surface tungstenized layer by depth-sensing nano-indentation measurement

“…Ti-Al-Nb alloys have been widely used for aerospace structural materials by virtue of their attractive mechanical properties, such as high specific strength, high resistance to hydrogen embrittlement and high elastic modulus (155-180 GPa) [1][2][3]. Moreover, the remarkable rapid development of the space industry has put forward demanding requirements on the surface mechanical properties of Ti-Al-Nb alloys.…”

Improvement of creep resistance in TiB particle reinforced Ti2AlNb composite particularly above 700 °C

“…Additionally the change of creep rate with increasing temperature in the composite is linear unlike that of the alloy. These results mean that the TiB particulate composite overcomes the disadvantage of the Ti 2 AlNb based alloy, abnormal degradation of creep resistance above 700 8C [2] and together with higher creep resistance than that of the alloy.…”

“…4, are almost on the prismatic plane. It has been reported that these prismatic dislocations in the Ti 2 AlNb alloy are generated from the bcc to O phase transformation during creep deformation and accelerate the creep rate above 700 8C [2]. Because the chemical composition of the composite will be same as that of the alloy, it can be expected that the thermodynamic reactions of the composite are same with that of the alloy during creep deformation.…”

“…Although this alloy has better mechanical properties at elevated temperatures than conventional alpha2 alloys, a rapid degradation of creep properties above 700 8C has been reported. This is due to the generation and emission of prismatic dislocations introduced by the bcc to O phase transformation [2]. The addition of a beta stabilizer was suggested to improve creep resistance in this temperature range, because the beta stabilizer keeps the bcc phase stable without phase transformation during creep deformation [3].…”

The Friction and Wear Properties of Ti–Al–Nb Intermetallics by Plasma Surface Alloying

“…The Ti-Al-Nb intermetallics have been studied as one of the potential materials for applications at high temperatures due to their high specific strength and stiffness as well as creep and oxidation resistance [1,2]. However, the poor wear resistance of Ti-Al-Nb becomes a principal obstacle for preparing tribological components, e.g., shafts, blades in gas turbines, engine valves, and turbochargers [3].…”