Advanced Materials Research Vol. 820

Abstract: Firstly, Magnesium oxide (MgO) whiskers were prepared by calcination of magnesium carbonate (MgCO₃₎ whiskers which were obtained by solution method. Then, surface-grafted MgO whiskers with poly (L-lactide) were synthesized by bulk ring-opening polymerization of L-lactide onto the surface of MgO whiskers. The MgO whiskers and surface-grafted MgO whiskers were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), x-ray diffraction (XRD) and fourier transformation infrared (FTIR). Results showed that MgO whiskers diameter in the range of 0.02-0.5μm, the length is between 10-80μm and well dispersed. A new characteristic stretching vibration absorption peak of C=O apppeared in the IR spectrum of the surface-grafted MgO whiskers, which suggested that poly (L-lactide) chains were successfully grafted on the surface of MgO whiskers.

Abstract: 800MPa grade Advanced High Strength Steels (AHSS), Complex Phase steel CP800, containing microalloying elements, are chosen to test the stamping properties in different test conditions and compared with traditional high strength low alloy (HSLA) steels HSLA S700MC. Tensile test, and HAT shape stamping test are taken to investigate the properties of the materials. Test results indicate that the studied 800MPa grade AHSS shows a better strength ductility balance compared with the reference HSLA steels. Under the same HAT shape springback stamping condition, HSLA steels S700MC always show the largest springback deformation among the investigated steels. While springback angles of all the AHSS studied are markedly smaller than that of steel S700MC. Among the 3 kinds of AHSS researched, CP800T always show the largest springback deformation. Domestic steel CP800 and imported CP800S show much smaller springback deformation respectively. In BHF of 100KN condition, springback deformation of 3 kinds of AHSS reaches the top value among all the BHF conditions. However, steel CP800 indicates an outstanding springback restrain trend in blank holding force (BHF) further increasing attempt. Thus, springback behavior can be restricted obviously by using a larger blank holding force (BHF) in steel CP800 stamping cases.

Abstract: This paper emphasis has researched the effect of particles scattering, surrounding thickness, heat treatment temperature and etc on microstructure, mechanics properties and macrostructure under different electric field of Ni/TiO₂, Ni/TiO₂/PAn Particles ER fluid, It is found that particles scattering, surrounding thickness, heat treatment temperature have major effect on shear stress and chain of particles.

Abstract: The effects of Nb content on the microstructure and properties of microalloyed rephosphorized steel sheet are investigated by analyzing its microstructure and properties of as hot-rolled and as annealed. The results show that proper coiling temperature for full precipitation increases as Nb content increases. Mechanical properties varies as the annealing temperature increases because of precipitation coarsening behavior, it is bad for mechanical properties stability.

Abstract: To obtain lead-free 0.5Ba (Zr_0.2Ti_0.8)O₃-0.5(Ba_0.7Ca_0.3)TiO₃ ceramics with excellent microstructure and electrical properties, BZT-BCT ceramics doping Mn⁴⁺ and Nb⁵⁺ was synthesized follow a conventional solid state reaction route. By means of SEM, XRD, quasi-static d₃₃ meter, the influence of sintering temperature on microstructure, piezoelectric and dielectric properties of BZT-BCT-Mn-Nb ceramics was discussed. The results show that grain size and the dielectric loss of BZT-BCT-Mn-Nb ceramics increase as raising the sintering temperature. When BZT-BCT-Mn-Nb ceramics is sintered at 1380°C, the optimum piezoelectric coefficient and dielectric constant are 264pC/N and 4142, respectively.

Abstract: To obtain high-entropy alloys (HEAS) coating with excellent properties on Q235 steel, a kind of HEAS powders was designed. The HEAS coating was prepared uniformly on Q235 steel by laser cladding. By means of OM, XRD and microhardness tester, the microstructure and properties of the high-entropy alloy layer were investigated. The experimental results indicate that the phases in the high-entropy alloy coating is mainly MoFeCrTiW with simple BCC, whose lattice parameter is a-3.1256Å. The microstructure in the coating is mainly cellular crystal, on which dispersion precipitates exist. And in the near bottom of the coating, there is few precipitates, in the middle part of coating, the precipitates are larger than that of bottom coating, while in near top of coating, dispersion precipitates become largest. The maximum microhardness value of coating reaches 800HV_0.98.

Abstract: Knitted-dapped metal rubber was developed to solve problems of metal rubber with low stiffness and test samples with different sizes were manufactured. Static tests and dynamic tests were carried out to study influences of density and thickness on the static stiffness and influences of frequency, amplitude and preload on dynamic characteristics. Results show that static stiffness rises when density or thickness increases. Frequency has little influence on dynamic characteristics. Knitted-dapped metal rubber will have smaller stiffness and better characteristics of damping, if amplitude increases; if preload increases, energy consumed in the vibration will be more.

Abstract: Binary compound Y₃Fe₂₉ cannot be directly formed by rare earth Y and Fe and the third element M (non-iron transition elements) must be introduced to form ternary compound Y₃(Fe,M)₂₉. In this work, six alloys with compositions of the Y₃Fe_29-xCr_x (x=1,2,3,4,5,6) were prepared and investigated by X-ray diffraction (XRD), Scanning electron microscopy (SEM) and differential thermal analysis (DTA). The study on the thermal stability of these compounds points to that the compoundY₃(Fe,Cr)₂₉ is a high temperature phase and exists above 1100K. The alloys with single-phase of Y₃(Fe,Cr)₂₉ was decomposed into Y₂(Fe,Cr)₁₇ and Y(Fe,Cr)₁₂ annealed at high temperature 1100K.

Abstract: A molecular dynamics simulation considered of chip deformation and force analysis for grinding process of Mg-Al alloy is presented. Hybrid potentials including embedded atom method (EAM) potential and Morse potential are applied in this model. The activities among atoms of Mg-Al Alloy material is described by EAM potential which is very suitable for metal materials. Morse potential is used to realize the interaction between Mg-Al alloy and abrasive grain made of diamond. Simulations of Different depths of cut (0.6nm, 0.8nm and 1.0nm) and different cut speeds (50m/s, 100m/s and 200m/s) are given. The experience result shows that with the same nanometric depth of cut, there is a little difference of ratio of the cut potential to the cutting speed. Moreover, with the same cutting speed, the cut potential is increased linearly with the depth of cut while reaching to stable cutting regime.

Abstract: Continuous research and innovation on intelligent material in recent years have greatly contributed to it applied into in every field and holding an irreplaceable position. The intelligent chromic material, one kind of intelligent materials, can make a reaction contingent on its located environment factors, besides, having abundant colors and abilities of dynamic changes with a strong decoration and innovation. The paper mainly focuses on study and analysis on application of intelligent material to the interior design, and attempts to bring new functions and stronger adaptive capacity to environment to the interior space, which is devoid for the traditional decorative materials, for the purpose of amelioration of peoples life quality.