Applied Mechanics and Materials Vols. 433-435

Abstract: The mechanism of ultrasonic assisted grinding is presented. Single factor experiment method was used to conduct experiments in order to reveal the effect of different grinding parameters (including feed rate, spindle speed, grinding depth) on surface roughness and grinding force of optical glass in ultrasonic assisted grinding and conventional grinding. The experiment data wss analyzed and it shows that the surface roughness and tangential grinding force decrease while the axial grinding force increase in ultrasonic assisted grinding process than that in conventional grinding process.

Abstract: The aim of this study is to investigate changes in microstructure and oxygen functional groups of liquefied wood activated carbon fibers using density functional theory, FTIR, X-ray photoelectron spectroscopy. Samples were immersed with hydrogen peroxide (H₂O₂) at three concentrations (15, 20, and 25 wt%), three temperatures (90, 70, and 50 °C) for three periods of time (1, 2, and 3 h). The results reveals that the pores average radius narrow, and micropores turn into mesopores or macropores with the increasing process, which brings about the surface area of treated samples decrease. Numerous oxygen functional groups are observed in the treated samples, and the ratios of oxygen and carbon increase from 3.2% before treated to 14.7% with H₂O₂ modification. The results confirm that the average pore radius and surface area decrease during treatment due to concentration and temperature. What is more, oxygen functional groups increase significantly with increasing treatment concentration.

Abstract: The thermal bending response of laminated composite plates has been studied by the use of various higher order shear deformation theories of Levinson, Touratier, Karama and Aydogdu. The governing differential equations are discretized by a meshless method based on inverse multiquadric radial basis function. The center deflections of laminated composite plates subjected to sinusoidal temperature distribution are solved and compared with available published results to assess the performance of the present method.

Abstract: This study has focused on the nitriding of 38CrMoAl steel by hollow cathodic auxiliary plasma nitriding. Nitriding time, temperature and potential of sample were chosen as the influencing factors of orthogonal experimentation. Also, the optimum technological conditions were determined. The testing results showed that the micro hardness of nitriding layer under the best technology of orthogonal experimentation rose noticeably which was 4 to 5 times higher than that of before. Besides, surface roughness of the plasma nitriding sample was as the same as that of before. What is more, there was a 3-μm-thickness white layer in the surface of nitriding sample which comprised ε and γ' phase, and the whole depth of nitriding layer reached 300 μm.

Abstract: Experimental studies on the compressive strength and frost resistance of rubber concrete during different maintenance period have been carried through in this paper. The results show that: the concrete compressive strength reduces with the incorporation of rubber particles, but its frost resistance increases, and with the growth of the maintenance period, its compression performance increases; however, its frost resistance remained unchanged.

Abstract: Interfacial reaction during wetting and spreading of Sn-Ag-Cu solder on Ni substrate is a key factor in order to improve the mechanical properties of the joints and the weld quality. Therefore, it’s important to focus on the thermodynamic and kinetic analysis of this interface reaction. In this paper, the sessile drop method was used to study the spreading contour evolution. The Kissinger method was used to calculate thermo-kinetic parameters of reactions between Sn-Ag-Cu solder and Ni substrate based on DTA data. The results show that Cu reduces activation energy and reaction rate of Sn-Ag-Cu/Ni system. (Cu, Ni)₆Sn₅ phase mainly constitute the interface reaction layer of Sn-Ag-Cu/Ni. As the temperature increases, partial (Cu, Ni)₆Sn₅ phase is substituted by Ni₃Sn₄ phase.

Abstract: The cutting characteristics of biomaterials (Ti-6Al-4V ELI) by tools are investigated with respect to cutting force, work piece surface roughness and tool flank wear by the vision system. Ti-6Al-4V ELI titanium turning is carried out with various cutting conditions; spindle rotational speed and feed rate. Back propagation neural networks (BPNs) are used for detection of tool wear. The input vectors of neural network comprise of spindle rotational speed, feed rates, vision flank wear, and cutting force signals. The output is the tool wear state which is either usable or failure. The detection of the abnormal states using BPNs achieves 97.5% reliability even when the spindle rotational speed and feed rate are changed.

Abstract: The corrosion of heavy rail steel is severity in south. Now there are not studies on the corrosion of heavy rail steel in atmosphere. The corrosion of heavy rail steel were studied by periodic infiltration corrosion test and electro-chemical testing technique in simulated industrial atmosphere. The result showed that U76CrRE has apparently more excellent anti-corrosion ability than that of steel U75V. The Cr and Re in U76CrRE enriched in local of base that promotes the rapid generation of α FeOOH and the increase of content. Thus the ability of the rust layer against the corrosive media from entering the layer was improved. Anti-corrosion capacity of heavy railroad steel in industrial atmosphere can be improved significantly by adding Cr and RE alloy.

Abstract: Automatic wood classifying system was developed to sort wood only from construction waste such as vinyl, plastic, and wood in order to produce renewable fuels. Automatic classifying processes are performed in the following order, step1: crushing, step2: analysis in the form of a mixture with water, step3: collection and transporting of floating materials, step4: classifying float materials with blower system. To classify a mixture of wood that are classified by air wind volume and classifying wood reliability can be varied depending on air wind volume. And, vinyl and plastic are difficult to classify due to increase in weight with water during the processes. Therefore, the number of times the experiment was repeated to get the optimal air volume to control it. In this experiment, the air wind volume is very important part.

Abstract: The cross-section shape change was investigated to determine the effects of proof stress, r value, wall thickness, and cross section in push-through bending of a square extruded pipe. Extruded A6063 aluminium alloy (40×40×2.0 mm) was used in the experiment. The push-through bending machine used has a six-axis NC controller. In this study, a two-dimensional single curvature shape was adopted in order to investigate the fundamental bending properties. A high-proof-stress material with severe bending workability was examined in this experiment to clarify the effect of bending workability on the material properties. Workability was evaluated by examining wrinkles and shape change of the cross section; the change in thickness was also evaluated, as were n and r values. The results are as follows. The high-proof-stress material was bent, resulting in significant cross-section deformation. The size of wrinkles caused by bending increased due to the large bending radius, and the wrinkles produced were deep. The effect of the r value on the cross-section deformation after bending could not be determined. In the present experiment range, the bending limit was determined by the size of wrinkles in internal bending. In A6063-T1, the wall thickness had a significant effect, and the forming limit of the thin-walled material was low. The bending limit was low for A6063-T5, and the effect of the wall thickness was slight. The bending limit of a 60×60mm cross-section piece was considerably lower than that of a 40×40 mm cross-section piece, for the same wall thickness; it was particularly significant in A6063-T5.