Effect of thermo-mechanical process on structure and high temperature shape memory properties of Ti–15Ta–15Zr alloy

The effect of thermo-mechanical treatment on microstructure evolution, martensite transformation, and shape memory behavior of Ti–15Ta–15Zr high temperature shape memory alloy were investigated. Different martensite morphologies were found with different annealing temperatures. The Ti–15Ta–15Zr alloy exhibits almost perfect shape memory recovery strain of 6% after annealing at 973 K for 0.5 h.     

Thermal stability and high-temperature shape memory characteristics of Ti–20Zr–10Ta alloy

The microstructure, martensite transformation behavior, thermal stability and shape memory behavior of Ti–20Zr– 10Ta high temperature shape memory alloy were investigated. The Ti–20Zr–10Ta alloy exhibited a reversible transformation with the high martensite transformation temperature of 500oC and good thermal stability. The alloy displayed the elongation of 15% and a maximum recovery stain of 5.5% with 8% pre-strain.     

Thermal stability and high-temperature shape memory characteristics of Ti-20Zr-10Ta alloyThermal stability and high-temperature shape memory characteristics of Ti-20Zr-10Ta alloy

The microstructure, martensite transformation behavior, thermal stability and shape memory behavior of Ti-20Zr- lOTa high temperature shape memory alloy were investigated. The Ti-20Zr-10Ta alloy exhibited a reversible transforma- tion with the high martensite transformation temperature of 500 ~C and good thermal stability. The alloy displayed the elongation of 15% and a maximum recovery stain of 5.5% with 8% pre-strain.     

Graphene-enhanced thermoelectric properties of p-type skutterudites

Nanocomposite is proved to be an effective method to improve thermoelectric performance.In the present study,graphene is introduced into p-type skutterudite La_(0.8)Ti_(0.1)Ga_(0.1)Fe_3CoSb_(12)by plasma-enhanced chemical vapor deposition(PECVD)method to form skutterudite/graphene nanocomposites.It is demonstrated that the graphene has no obvious effect on the electrical conductivity of La_(0.8)Ti_(0.1)Ga_(0.1)Fe_3CoSb_(12),but the Seebeck coefficient is slightly improved at high temperature,thereby leading to high power factor.Furthermore,due to the enhancement of phonon scattering by the graphene,the lattice thermal conductivity is reduced significantly.Ultimately,the maximum z T value of La_(0.8)Ti_(0.1)Ga_(0.1)Fe_3CoSb_(12)/graphene is higher than that of graphene-free alloy and reaches to 1.0 at 723 K.Such an approach raised by us enriches prospects for future practical application.     

Microstructural,phase transformation and magnetic properties of Ni-Mn-Ga alloy fabricated by spark plasma sintering

The microstructural,phase transformation and magnetic properties of Ni-Mn-Ga alloy fabricated using the spark plasma sintering method have been investigated. The results show that both the as-sintered and annealed sintered specimens exhibit typical martensitic transformation behaviours. The martensite of the sintered specimen after annealing exhibits a ferromagnetic nature. Moreover,study of the fracture surface indicates that the transgranular fracture contributes to the higher ductility of sintered Ni-Mn-Ga alloy. In addition,the transformation strain in sintered Ni-Mn-Ga alloy is studied for the first time.