The microstructural and mechanical properties of β-type Ti_85-xNb_10+xSn₅ (x = 0, 3, 6, 10 at.%) alloys with low elastic modulus were investigated. The experimental results show that the Ti₈₅Nb₁₀Sn₅ and Ti₇₅Nb₂₀Sn₅ alloys are composed of simple α and β phases, respectively; the Ti₈₂Nb₁₃Sn₅ and Ti₇₉Nb₁₆Sn₅ alloys are composed of β and α″ phases. The content of martensite phase decreases with the increase of Nb content. The Ti₈₂Nb₁₃Sn₅ and Ti₇₉Nb₁₆Sn₅ alloys show an inverse martensitic phase transition during heating. The Ti₈₅Nb₁₀Sn₅ and Ti₈₂Nb₁₃Sn₅ alloys with the small residual strain exhibit the good superelastic properties in 10-time cyclic loading. The reduced elastic modulus (E_r) of the Ti₇₅Nb₂₀Sn₅ alloy (61 GPa) measured by using the nanoindentation technique is 2–6 times of that of human bone (10–30 GPa), and is smaller than that of commercial Ti-6Al-4V biomedical alloy (120 GPa). The Ti₇₅Nb₂₀Sn₅ alloy can be considered as a novel biomedical alloy. The wear resistance (H/E_r) and anti-wear capability (H³/E_r²) values of the four alloys are higher than those of the CP–Ti alloy (0.0238), which indicates that the present alloys have good wear resistance and anti-wear capability.

Effect of Fe addition on microstructure and mechanical properties of as-cast Ti₄₉Ni₅₁ alloy were investigated. The experimental results shows the microstructures of Ti_48.5Ni₅₁Fe_0.5 and Ti₄₈Ni₅₁Fe₁ alloys are mainly composed of TiNi matrix phase (body-centered cubic, BCC), Ti₃Ni₄ and Ni_2.67Ti_1.33 phases; the microstructure of Ti₄₇Ni₅₁Fe₂ alloy is mainly composed of BCC TiNi, Ti₃Ni₄, Ni_2.67Ti_1.33, and Ni₃Ti phases; the microstructure of the Ti₄₅Ni₅₁Fe₄ alloy is mainly composed of TiNi, Ti₃Ni₄ and Ni₃Ti phases. The Ni₃Ti nanocrystalline precipitates at the adjacent position of Ni_2.67Ti_1.33 phase. The Ti_48.5Ni₅₁Fe_0.5 and Ti₄₈Ni₅₁Fe₁ alloys have high yield strength and fracture strength, and can be as the engineering materials with excellent mechanical properties. In addition, the Ti_48.5Ni₅₁Fe_0.5 alloy with the low elastic modulus and large elastic energy is also a good biomedical alloy of hard tissue implants. The fracture mechanism of the four alloys is mainly cleavage fracture or quasi-cleavage fracture, supplemented by ductile fracture. The experimental data obtained provide the valuable references in application of as-cast alloys and heat-treated samples in the future.

In order to know the influence of laser power on the steel (27SiMn) used for repairing the column with Inconel 718 powder materials, and to obtain the optimal laser power parameters with the best mechanical properties of cladding layer, the microstructure, tensile properties and fracture morphology of the Inconel 718 alloy under three laser powers (1800 W, 2100 W and 2400 W) were investigated by using the single-factor variable method, keeping the scanning speed, powder feeding amount and spot diameter unchanged. The results show that with increase of laser power the mechanical properties of the Inconel 718 alloy coating prepared on the surface for the column steel gradually decreased, and the mechanical properties were the best when the laser power is 1800 W. The yield strength of Inconel 718 alloy coating prepared at 1800 W was 61.7% higher than that of the substrate, and its value is 970 MPa. The elongation is reduced by 50% compared with the substrate, and its value is 7%. The microstructure of 27SiMn steel with cladding coating is (Ni, Fe, Cr) phase and Ni₃Fe phase, and the microstructure of the coating is mainly composed of uniform cellular crystals. This study provides a valuable reference for the additive manufacturing of industrial materials of 27SiMn steel with laser-cladding coating.