Advanced Materials Research Vols. 194-196

Abstract: Vitrification is considered as an attractive procedure for municipal solid waste incineration ash, which can realize the volume reduction and innocent treatment of incineration ash, as well as reuse of bottom ash. The main oxide components of molten ash slag are CaO, Al₂O₃, SiO₂, Fe₂O₃, MgO, and Na₂O, accounting for more than 90% of the total mass. The phase relations and thermodynamic properties of the CaO-Al₂O₃-SiO₂-FeO_x-MgO-Na₂O oxide system is highly required, and is of great significance for optimization of vitrification processing and sustainable resource utilization of melting slag. A study on the equilibria phase relations of CaO-SiO₂-MgO-FeO_x system was done by applying CALPHAD based on FactSage in this paper. The modeling parameters for the thermodynamic properties of liquid phase in CaO-SiO₂-MgO-FeO_x system were established and the equilibrium phase relations of MgO-SiO₂-FeO_x and CaO-SiO₂-FeO_x-MgO systems were calculated for different temperatures and oxygen partial pressures.

Abstract: β-Sialon powder was synthesized by in-situ carbothermal reduction-nitridation process, with fly ash and carbon black as raw materials. The influence of raw materials composition on synthesis process was investigated, and the phase composition and microstructure of the synthesized products were characterized by X-ray diffraction and scanning electronic microscope. The carbothermal reduction-nitridation reaction process was also discussed. It was found that increasing carbon content in a sample could promote the decomposition of mullite in fly ash and the formation of β-Sialon. The β-Sialon could be synthesized at 1550°C for 6h by heating the sample with the mass ratio of fly ash to carbon black of 100:56. The β-Sialon as-received in this study existed as granular with an average particle size of about 2μm. The carbothermal reduction-nitridation reaction process consisted of the nitridation processes of mullite, SiO₂ and Al₂O₃ in fly ash as well as the conversion process of X-Sialon to β-Sialon.

Abstract: The oil-tea cake, as the major byproduct of tea oil production, was used with phenol-formaldehyde (PF) resin to prepare a mixed interior plywood panel adhesive (TC-PF adhesive). The optimum formulation of this adhesive and the optimum hot-press conditions for making plywood panels were investigated in this work. The results showed that wet shear strength value of TC-PF adhesives increased when the addition level of PF resin increased. TC-PF adhesive with 50% PF resin addition had a relatively low cost, and moreover pass the bonding strength requirement of China Industry Standard for interior plywood panels. Hot-press temperature and hot-press time had obvious influence on bonding performances of plywood panels. When the hot-press temperature was in the range of 140°C-160°C, the wet shear strength value of panels bonded with the adhesives passed the China Industry Standard requirement. At 3-5min of hot-press time, the plywood panels had satisfactory wet shear strength.

Abstract: Hydrogen production of photosynthetic bacteria group (PSBG) was studied using corn stalk hydrolyzate as hydrogen production substrate. The effects of sulfuric acid concentration, hydrolysis pH values and hydrolysis temperature on hydrogen production were investigated. The optimum process conditions were as follows: the sulfuric acid concentration was 1%, hydrolysis pH value was 6.0 and the hydrolysis temperature was 110°C , respectively. Three hydrolyzate detoxification methods were compared. The method of calcium hydroxide obtained the optimal detoxification effect and the maximum hydrogen yield was 472 mL H₂/ (L-medium).

Abstract: The paper studies the forming process of high inner-pressure hydroforming of T-branch tube by using DYNAFORM finite element simulation software based on its technology characteristics. First, the effects of different loading paths of key parameters(internal pressure, axial extrusion force, radial back force) on T-branch tube hydroforming process have been studied. The studies show that enough feed rate is essential to obtaining a certain branch height but excess feed rate can lead to the thickness seriously increased. The way of influence of internal pressure is contrary to radial back force, both excess internal pressure and slight radial back force can cause top branch thinned or fractured. If branch height is too low, radial back force will obstruct the extension of tube and productions cannot be compliance with design requirements. Second, the effects of coefficient of friction and radius of round angles on forming quality of T-branch tube have been discussed. The studies show that forming quality is better when the coefficient of friction is smaller or radius of round angles is larger.

Abstract: Finite element simulation software Deform-3D on large-diameter multi-pass three-way pipe to simulate the extrusion process, the equivalent stress, equivalent strain and load were analyzed. The simulation results show that with the increase of processing pass, deformation process becomes complex, forming more difficult, the value of the state variables are increasing; in the extrusion process, the mold first contact with the billet and extruded convex hull area of the site, compared to other regions, plastic deformation, stress concentration and large, with the mold closed, the force to uniform .The results are well shown that it could provide a theoretical basis to the practical industrial production.

Abstract: FEM simulations of squashing and bending process of large diameter elbow was applied to analyze the influence of squashing velocities, one of the key process parameters, on the deformation of the tube. In this study the squashing distance of first step is 300mm after several simulation attempts, corresponding to different squashing speeds and different bending velocities of second step. The simulation results of different velocities are compared and discussed. In the end the final velocities of the two steps are given.

Abstract: Nano Zn-Fe coatings in a chloride electrolyte with additives by reverse pulse current were obtained and the anticorrosion was investigated. The morghology and crystal size of Zn-Fe alloy depositions were measured by scanning electron microscope and atom force microscope. Coatings with 30 nm or so crystal size was obtained with mean current density 9.0 A•dm^-2, duty cycle 60%, frequency 500 Hz and time of negative to positive 30 ms ∶8 ms. It was detected by X-ray diffraction that the pulse plated coatings of Zn–Fe were mixtures of two phases, one of them being the α-phase and the other pure zinc or the α-phase with a significantly lower proportion of Fe. The pulse plated Zn-Fe coatings’ corrosion resistance was greatly improved compared with Zn-Fe coatings by direct current according to Tafel tests, saline immersion and salt spray tests. The anticorrosion of Zn-Fe coatings with 30 nm crystal size was 2~3 times than that of normal Zn-Fe alloy deposits.

Abstract: Along with the development of the measuring technique and computer technology, market competition is aggravating, the modern product of the design cycle demands shorter especially in automobile field. In order to meet the development requirements of automobile, we must reduce the design cycle and cost, so the Reverse Engineering (RE) technique has applications widely. This paper describes some concepts about reverse engineering. It points out the key technologies in reverse engineering like cloud data processing technology and surface reconstruction technology. Finally this paper uses the reverse engineering software CATIA to recover one inner automobile panel and describes the process of reverse engineering in details to build 3D model.

Abstract: The growth of amorphous carbon films via deposition is investigated using molecular dynamics simulation with a modified Tersoff potential. The impact energy of carbon atoms ranges from 1 to 50 eV and the temperature of the diamond substrate is 300 K. The effects of the incident energy on the growth dynamics and film structure are studied in a detail. Simulation results show that the mobility of surface atoms in the cascade region is enhanced by impacting energetic carbon ions, especially at moderate energy, which favors the growth of denser and smoother films with better adhesion to the substrate. Our results agree qualitatively with the experimental observation.