Applied Mechanics and Materials Vols. 190-191

Abstract: Co₂Z type planar hexaferrite doping of Nd³⁺ 2CoO·3BaO ·xNd₂O₃·(10.8-x) Fe₂O₃ is made with common production process of cermet. The paper studies the influence of Nd₂O₃ doping quantity on microstructure and magnetic performance of Co₂Z type planar hexaferrite. The result indicates that Nd³⁺ doped Co₂Z type ferrite still keeps structure of Z type planar hexagonal, when the doping quantity x=0.050, the magnetic performance in ultrahigh frequency will get improved, the initial permeability can grow to 13, and the cut-off frequency will also relatively reduce to the lowest value 2.131GHz.

Abstract: The effects of pyrolysis temperature on the yields of char ,oil and gas produced in the waste tire pyrolysis process ,the effects of temperature on the concentration of gas and pyrolysis oil constitutes, and the effects of HY-51 (as catalyst) on the yields and on the concentration of gas constitutes, were studied in detail. The experiments showed that the effects of pyrolysis temperature on liquid and gas products were important. The yields of the gas were primate raised, then reduced. When the pyrolysis temperature reached 550°C, the yields of oil can reach to above 45%. when adding catalyst, the yields raised to 50%.Gas product were component of H2, CH4, CO,CO2 and C2-C3, etc., there were a lot of macromolecular aromatic, and contain acid, hydrocarbon, ketone, heterocyclic (containing S, O, N, etc)in pyrolysis oil. we had been done the thermogravimetric experiments. Which were indicated that waste tire have three main mass loss stages. The range of first stage temperature was 200-350°C, 270°C was the maximum temperature of mass loss ,and the mass loss rate reached to 20.4%;The second stage mass loss temperature was 350-600 °C, the biggest temperature mass loss were in 484 °C and 547 °C, this stage rate was 64.6%; the range of the third stage was 600-675 °C, had a small mass loss peak, the rate just was 2.5% The pyrolysis oils analysis were provided the basic data for the chemical and energy basic on pyrolysis and pyrolysis characteristic of the waste tire.

Abstract: In order to improve the wear-resisting properties of titanium alloy surface, reactive electric spark deposition was carried out using a graphite electrode in a nitrogen gas atmosphere, and TiCN/Ti based composite coating was fabricated on TC4 titanium alloy surface. The surface morphology, microstructure, interfacial behavior between the coatings and substrate, phase and element composition of the coatings were investigated by scanning electron microscope（SEM), X-ray diffraction (XRD) and Auger electron spectroscopy (AES). The microhardness hardness distributions as a function of depth were measured by a micro-hardness tester. The results show that the coating about 20μm thick is continuous, close, and completely covering the substrate surface and mainly composed of the TiCN phase which is in-situ synthesized by the reaction among titanium from the substrate, carbon from the graphite electrode and nitrogen from the shielding nitrogen gas. The coating has a strong metallurgical bonding and adhesion to the substrate. Microhardness profile falls off with the coatings thickness increasing and the highest microhardness values of the superficial coating could be up to 1496HV, which is six times more than that of the substrate.

Abstract: A novel gadolinium double-decker sandwich-type complex with tetrabenzoporphyrin (TBP) ligands-Gd(TBP)2 was synthesized by the reaction of porphyrin 1 with Gd(acac)3. nH2O in boiling 1, 2, 4-Tcb for 15~17 h under Ar. Its structure is characterized byUv-Vis-NIR and HR-MS. The spectroscopic properties show that the longest-wavelength visible band (600-800 nm) and the strong near-IR absorption band centered near 1340 nm of Gd (TBP)2 complex are obviously red-shifted due to the extension of the π conjugated systems derived from the linear benzoannulation in the TBP ring. The magnetic studies also indicate that the observed value of χMT of Gd(TBP)2 complex is close to the combined value of Gd(III) and porphyrin radical anion at room temperature, and antiferromagnetic interaction that possibly results from the intramolecular spin exchange between the porphyrin π-radical electron, and the gadolinium f unpaired electrons dominates its magnetic properties over the whole temperature range. Since the first report of bis(porphyrinato) metal complexes M(Por)2 such as a cerium(IV) bisporphyrinate, Ce(TPP)2 and hydrogen praseodymium(III), PrH(TPP)2 in 1983[1], sandwich-type rare earth complexes with porphyrin ligands have received increasing attentions due to the unusual physical, spectroscopic, redox, electron transfer, and/or conductivity properties resulting from their strong π-π interactions[2-4]. Whereas the chemistry and properties of homoleptic sandwich complexes containing the same pophyrinato ligands of various lanthanide, actinides and group 4 transition metals have been extensively studied[5-6], actually all of them are confined to the sandwich-type complexes containing meso-substituted porphyrin ligands except for octaethylporphyrin (OEP) or octamethylporphyrin (OMP). Little is known about sandwich-like complexes with aromatic ring-fused porphyrin ligands that contain a more delocalized π system. In this paper, we will describe the preparation of a novel gadolinium homoleptic double-decker sandwich-type complex with tetrabenzoporphyrin (TBP) ligand (see Fig.1) as well as their spectroscopic characterization and magnetic studies.

Abstract: In this paper, the drying experiments of paper sludge were performed at different drying conditions. The drying kinetics and phenomena of paper sludge were investigated. The effective diffusivity and the activation energy of the paper sludge during drying had been evaluated. At the same time, seven empirical models were used to model the experimental data, such as Newton, Page, Modified Page, Henderson and Pabis, Logarithmic, Two term, Two Term exponential et al. Three statistical parameters (The coefficient of determination (R2), root mean square error (RMSE) and the residual sum of square (RSS) ) were used to evaluate goodness of fit of the tested models.

Abstract: A TiCN cermet composite coating was fabricated on 45# steel substrate by reaction nitrogen arc welding cladding technique. The mixture powder of titanium and graphite was preplaced onto the 45# steel substrate after intensive mixing by star ball-mill and gluing with starch binder. The microstructures and phase of the coatings, interracial behavior between coatings and the substrate were investigated by scanning electronic microscope, X-ray diffractometer. The microhardness distribution of the coating section, frictional coefficient, abrasion loss and wearing surface morphology were investigated by microhardness tester, abrasion machine and scanning electronic microscope. The results show that an excellent bonding between the coatings and the 45# steel substrate is ensured by the strong metallurgical interface and phase of the coatings are mainly composed of TiCN. The highest microhardness of the coatings reaches HV _0.5 810, which is about 3 times more than that of the 45# steel substrate. The anti-abrasive test results show the coating has better anti-abrasive performance than the 45# steel substrate.

Abstract: A woodceramics makes from liquefaction wood and wood powder, the basic property connects with sintering temperature and liquefaction wood content. Thermo gravimetric analysis indicates that higher liquefaction wood content lead to reduce the weight loss. Scanning electron microscopy observation shows that wood powder is as a natural plant template and the basic structure of wood can partly keep. The apparent density increases before about 1100°C, and then decreases as temperature gets further; but the apparent porosity increases continuous; bending strength increases from 8.45 MPa to 11.87 MPa when the liquefaction wood content raises 60%-120%. Meanwhile, elevation of liquefaction wood content and sintering temperature can reduce abrasion loss.

Abstract: This paper provides a detailed description of high strength architectural heavy plates with 80mm in thickness developed at Wuhan Iron and Steel（Group）Corporation(WISCO). The chemical composition of plates contains mainly C-Mn-Nb-V-Ti with proper content of other alloys, and the thermal-mechanical controlled process and normalizing treatment were applied. The results show that the base plates manufactured at WISCO have a good match of high strength, good through-thickness characteristic, low yield ratio and low temperature toughness with fine microstructure, and the fracture transition temperature is about -40°C. The welding plate also has high strength and good low temperature toughness which comprehensively meet the technical requirement of large-scale architectural buildings.

Abstract: This study selected sodium silicate, sodium fluoride, glycerol hydroxyl acid, potassium hydroxide and phosphine oxide (LAP) as the stabilizer electrolyte, and then on micro-arc oxidation of magnesium with constant current density. The microstructure, corrosion resistance, chemical composition, structure and characterization of micro-arc oxidation film were determined by SEM and anodic oxidation methods. Experimental results indicated that the test pieces of magnesium would formed an silver-gray uniform densification oxide film on the surface by micro-arc oxidation treatment, and the corrosion resistance of magnesium film-formed had increased by potentiodynamic polarization curve testing.

Abstract: In this study, a constant current density was used in magnesium microarc oxidation treatment. The microstructure, chemical composition, phase composition and corrosion resistance of the micro-arc oxidation film were characterized by XRD and EDS. The experimental results showed that the test pieces of magnesium would formed an silver-gray uniform densification oxide film on the surface, the film-formed materials was amorphous by XRD analysis, and on this basis we preliminary discused the film-forming mechanism.