Effect of Homogenization Annealing on Wear Properties of Thixo-Extrued Copper Alloy

The semi-solid extruded CuSn10P1 alloy bushings were homogenization annealed. The effects of annealing process on the hardness and wear properties of bushings were researched. The results show the Brinell hardness increases firstly and then decreases with the increase of annealing temperature and annealing time. With the annealing temperature increasing, the grinding loss rate and friction factor decrease firstly and then increase. At the annealing time of 120 min, the grinding loss rate decreases from 7% at the annealing temperature of 450 °C to 6% at 500 °C, and then increases from 6% at 500 °C to 12% at 600 °C. The friction factor decreases from 0.54 to 0.48 and then increases to 0.83. At the annealing temperature of 500 °C, the grinding loss rate decreases from 11% at the annealing time of 60 min to 6% at 120 min, and then increases to 15% at 150 min. The friction factor decreases from 0.67 to 0.48 and then increases to 0.72. The best wear performance and Brinell hardness can be obtained at annealing temperature of 500 °C for 120 min.

Effect of Structural Deficiencies on Bi-Ferroic Behaviors of Lead-Free Bi0.5 Na0.40K0.10TiO3 Films

Lead-free Bi0.5Na0.4K0.1TiO3 (BNKT) ferroelectric films on Pt/TI/SIO2/Si substrates were prepared via a sol-gel spin coating routine. The microstructures and multiferroic behaviors of the films were examined intimately as a function of the annealing time. A rise of annealing time enhanced the crystallization of the films via the perovskite structure. The multiferroic behavior, including simultaneously the magnetic and ferroelectric orders, was observed altogether the films. When the annealing time rose, ferroelectric and magnetic properties were found significantly increased. The remnant polarization (Pr), also as maximum polarization (Pm) respectively increased to the very best values of 11.5 µC/cm2 and 40.0 µC/cm2 under an applied electric field of 500 kV/cm. The saturated magnetization (Ms) of films increased to 2.3 emu/cm3 for the annealing time of 60 minutes. Oxygen vacancies, originating from the evaporation of metal ions during annealing at high temperatures are attributed to the explanation for ferromagnetism within the BNKT films.

Characterization and Hydrogen Storage Capacity Analysis of Dip Coated Lithium Aluminium Hydride Thin Films

Complex metal hydrides are one of the most effective hydrogen storage materials due to their unique property to absorb and desorb hydrogen with the hydrogen storage capacity of about 5-7 wt%. In this study, lithium aluminium hydride (LiAlH4) was coated on glass substrate using dip coating method. The coating conditions investigated were LiAlH4 concentrations of 6 g/l, 10 g/l and 20 g/l and post-annealing time from 0 to 60 min. Phase and grain size of the deposited LiAlH4 were analyzed using X-ray powder diffraction (XRD). Scanning electron microscope (SEM) was used for surface morphology analysis. The hydrogen storage capacity of the deposited thin films was analyzed using thermogravimetric analysis (TGA). The experimental results revealed that the phase of the deposited LiAlH4 thin films on glass substrate were mixed with lithium aluminium hydroxide hydrate (LiAl2(OH)7·2H2O) and lithium hexahydroaluminate (Li3AlH6). The intensity of the LiAl2(OH)7·2H2O and LiAlH4 peaks tends to decrease with increasing LiAlH4 concentration and post-annealing time while the intensity of the Li3AlH6 peaks increased with increasing LiAlH4 concentration and post-annealing time. The grain size was decreased with increasing LiAlH4 concentration and post-annealing time. The smaller grain size the better the hydrogen storage capacity. The hydrogen storage capacity of the deposited LiAlH4 thin film was increased from 0.124 wt % using LiAlH4 concentration of 6 g/l without post-annealing to 1.675 wt % using LiAlH4 concentration of 20 g/l with 60 min post-annealing time.

Effect of Holding Time of Decarbonization Annealing on Recrystallization in Fe-3.2%Si-0.047Nb% Low-Temperature Oriented Silicon Steel

In this study, the effects of decarburization annealing time on the primary recrystallization microstructure, the texture and the magnetic properties of the final product of 0.047% Nb low-temperature grain-oriented silicon steel were investigated by means of OM, EBSD and XRD. The results show that when the decarburization annealing condition is 850 °C for 5 min, the uniform fine primary recrystallization microstructure can be obtained, and the content of favorable texture {111} < 112 > is the highest while that of unfavorable texture {110} < 112 > is the lowest, which is mostly distributed near the central layer. At the same time, there are the most high-energy grain boundaries with high mobility in the primary recrystallization microstructure of the sample annealed at 850 °C for 5 min, and the ∑9 boundary has the highest percentage of grain boundaries. The samples with different decarburization annealing time were annealed at high temperature. It was found that perfect secondary recrystallization occurred after high-temperature annealing when the decarburization annealing condition was 850 °C for 5 min. The texture component was characterized by a single Goss texture, and the size of the Goss grain reached 4.6mm. Under such annealing conditions, the sample obtained shows the optimal soft magnetic properties of B800 = 1.89T and P1.7/50 = 1.33 w/kg.