Fig. 1. Stress-induced continuous elastic softening of Ti2448 alloy by a novel MT: (a) cyclic stress-strain curves with a total strain of 6% at an interval of 1% (measured at 293?K); (b) an enlarged curve in a with the cycle strain up to 1% showing that the softening starts at the beginning of the loading; (c, d) 2D synchrotron X-ray diffraction (SXRD) profiles measured at 400?K and 100?K, showing the single β phase without the thermal-induced MT; (e) 2D SXRD profile of the unloaded alloy after 9% deformation (both measured at 300?K), showing the stress-induced MT to the α” martensite.

Fig. 2. Nano-scale Nb modulation and its induced periodical properties: (a) three examples of 3D Nb-rich iso-concentration surfaces, where Nb is 18.5, 17.0 or 16.5 at.% (left to right); (b) a pair of 2D cross-sections showing Nb and Ti distributions; (c) schematics of 1D periodical Nb modulation, and the corresponding periodical variations of both elastic modulus (E) of the β phase and its MT strain (εMT) to form the α” martensite.

Fig. 3. The combined SE and high strength in wide temperature range: (a) both SE and SM strains vary with T; (b) new relation of the recovered strain with the MT strain (the data of Ti2448 alloy measured at 77?K); (c) highσ/E ratio and its inverse strengthening relation with other metallic materials noted by the linear arrow.

Fig. 4. Tunable thermal expansion in a wide temperature range up to 573?K: (a) unstable thermal expansion for the first heating cycle, a step to control the followed heating cycle stability; (b) thermal expansion being normal, zero (LTE) and negative (NTE) for the second cycle. Note that the contraction is ~0.2%, which is much lower than the value of ~0.9% for the first heating; (c) thermal stable NTE for 25?32 heating cycles; (d) tuning the coefficient of thermal expansion (CTE) via pre-deformation.