The hot compression behavior of as-extruded AZ31 magnesium alloy was investigated to study the effect of compression temperature and strain on microstructure evolution, grain orientation, and texture evolution. The thermal compression tests of AZ31 Mg alloy were carried out on the Gleeble-3800 simulation device: With constant strain, the temperatures were 250, 300, 400, and 500 °C, respectively; at constant temperature, the strains were 0.2, 0.4, 0.6, and 0.8, respectively. After observation and analysis of compressed samples, it is found that with 0.65 strain and 0.05 s−1 strain rate, grains were equiaxed, well refined, and distributed uniformly at 400 °C. At this temperature, new orientation between {0001} and $\left{\rm\char123} {12\bar{1}0} {\rm\char125} \right$ or $\left{\rm\char123} {01\bar{1}0} {\rm\char125} \right$ appeared in grains; new texture components close to $\left{\rm\char123} {\bar{1}\bar{1}22} {\rm\char125} \right$ and $\left{\rm\char123} {1\bar{2}12} {\rm\char125} \right$ pyramidal textures were formed, but whole texture strength was weakened and anisotropy of the sample was reduced. With the increase of strain, grains became smaller and volume fraction of DRX grain became higher; the original basal texture was replaced by prismatic textures; after 0.4 strain, the increase of strain did not change the texture component, but only the pole density.

A homogeneous structured CoCrNi medium-entropy alloy was synthesized by gas atomization and spark plasma sintering (SPS). The mechanical properties, corrosion resistance, and magnetic properties were reported in this study. The as-atomized CoCrNi MEA powder, with a spherical morphology in shape and a mean particle diameter of 61 μm, consisted of a single face-centered cubic (FCC) phase with homogeneous distributions of Co, Cr, and Ni elements. Also, the cross-sectional microstructure of powder particles gradually transformed from fully cellular structure into equiaxed-type structure with increasing particle size. After being sintered by SPS, the CoCrNi MEA consisted of a single FCC phase with a mean grain size of 20.8 μm. Meanwhile, the CoCrNi MEA can capable of offering an ultimate tensile strength of 799 MPa, yield strength of 352 MPa, elongation of 53.6%, and hardness of 195.3 HV. In addition, this MEA showed superior corrosion resistance to that of 304 SS (stainless steel) in both 0.5 mol/L HCl and 1 mol/L NaOH solutions. The magnetization loop indicated that this MEA has good soft magnetic properties.

Bi0.5Na0.5TiO3 (BNT)-based lead-free materials are important for piezoelectric actuator, and several researchers have studied the effect of B-site complex ion doping on strain in (Bi0.5Na0.5)TiO3–SrTiO3. In this work, a paraelectric perovskite Sr(Zn1/3Nb2/3)O3 (SZN) with B-site complex structure was introduced into 0.80(Bi0.5Na0.5)TiO3–0.20SrTiO3 (BNTST) to investigate the phase structure and electrical properties as well as the field-induced strain behavior. The results showed that SZN substitution decreases the rhombohedrality 90-γ and induces the transition from dominant ferroelectric to nonergodic relaxor by shifting its TF-R to lower temperatures. Moreover, the field-induced ferroelectric domains cannot remain stable at room temperature when SZN substitution is large than 1.0 mol%. These behaviors induced the transition between nonergodic relaxor and ergodic relaxor, which contributed to its large strain and related properties. In this work, this material gave the largest bipolar strain of 0.43% and large normalized unipolar strain of 505 pm/V at the SZN content of 2 mol% under 8 kV/mm, and showed good temperature stability up to 100 °C. The above encouraging results may be helpful for further investigation of BNTST-based ternary systems in search of a potential Pb-free piezoelectric material.

In this work, the nitrogen-doped carbon materials (NCM) and nitrogen/sulfur codoped carbon materials (NSCM) were prepared using conventional benzoxazine (BOZ) and sulfur-containing benzoxazine as precursor and SBA-15 as template. The morphology, structure, and electrochemical performance of carbon materials were characterized by scanning electron microscopy, transmission electron microscopy, the X-ray diffraction, X-ray photoelectron spectroscopy, nitrogen adsorption–desorption, cyclic voltammetry, and galvanostatic charge–discharge. The results show that the as-prepared carbon materials have ordered mesoporous structure, large specific surface area, and excellent electrochemical properties. The NSCM treated at 800 °C exhibit an extremely high specific capacitance of 550 F/g at the current density of 0.5 A/g in 0.5 mol H2SO4 electrolyte, which shows great improvement compared with NCM. The nitrogen/sulfur codoping is suggested to be a very effective method to improve the performance of carbon materials, and the NSCM should be a promising candidate as electrode materials for supercapacitors.