The corrosion behavior of the Ti–6Al–4V alloy was investigated in a sulfate-reducing bacteria (SRB) solution. The results showed that sulfate-reducing bacteria has good affinity with the surface of the Ti–6Al–4V alloy after 5 days. A potentiodynamic polarization test demonstrated that the corrosion resistance of the Ti–6Al–4V alloy was initially improved but deteriorated quickly in the subsequent period. The corrosion mechanism of the Ti–6Al–4V alloy was revealed by analyzing its microstructure with the aid of scanning electron microscopy, X-ray photoelectron spectroscopy and X-ray fluorescence. The pitting corrosion was deemed to be a typical cause of the corrosion behavior of the alloy in the SRB solution. The underlying mechanism of the pitting corrosion was proposed for the alloy.

The effect of rare earth Gd on the microstructure, martensitic transformation and magnetic properties of Ni₄₅Co₅Mn₃₅In_15−xGd_x (0 ≤ x ≤ 1.6) alloys is investigated. The addition of Gd results in a change in the microstructure. With the increase of Gd content, the grain size is clearly reduced and the volume fraction of the second phase increases gradually. And then the second phase along the grain boundaries grows and connects to each other. Some disperse in the grains. One-step thermoelastic martensitic transformation is observed in Ni₄₅Co₅Mn₃₅In_15−xGd_x alloys. When the Gd content reaches 0.8 (at%), the martensite transformation temperature decreases first, and then rises with the increase of Gd content. The near-room-temperature magnetocaloric effect (MCE) in polycrystalline Ni₄₅Co₅Mn₃₅In_14.2Gd_0.8 alloys is observed. The magnetic-field-induced inverse phase transformation from martensite to austenite phase is confirmed. The inverse magnetic entropy change (ΔS_M) reaches 17.78 J/kg K for Ni₄₅Co₅Mn₃₅In_14.2Gd_0.8 alloy at 277 K and its R_c is about 356 J Kg⁻¹ at an applied field of 5 T.

Microcrystalline diamond powders are deposited directly by a HFCVD apparatus with adding amounts of trimethyl borate in gas mixture. The study establishes the relationship between the boron...

The behavior of magnetostructural transition and the magnetocaloric effect in the MnCoGe_1.02−xGa_x (x = 0, 0.02, 0.04, 0.06) alloys are investigated in this study. The addition of Ga changes the crystal structure of MnCoGe_1.02−xGa_x alloys at room temperature and reduces the phase transition temperatures with increasing Ga content. The coupling of magnetostructural transition and negligible magnetic hysteresis is observed in the Mn-Co-Ge-Ga alloy. At 305 K, under the action of a 5 T magnetic field, the MnCoGeGa_0.02 alloy exhibits 23.47 J/kg∙K magnetic entropy change, and its refrigeration capacity reaches 387 J/kg. The large magnetic entropy change near room temperature and the high refrigeration capacity in the Mn-Co-Ge-Ga alloy make it a promising new type of refrigeration material.