Advanced Materials Research Vols. 472-475

Abstract: Structure and properties of variant aramid fibers were investigated. The correlation of the tensile modulus and orientation were developed in accordance with model proposed by Northolt. Combined orientation angle with paracrystalline parameter, the predicted modulus is well fitting with the experimental date using the equation proposed by Rao. It is concluded that the tensile modulus is determined by both orientation and paracrystalline parameter, especially in higher tensile modulus fibers. The line chain modulus is 236Gpa derived from the model and close to the theoretical crystal modulus.

Abstract: GSCM and its members of sharing resources generate knowledge spillover phenomenon within innovation activities.Considering the scarcity and publicity characteristics of knowledge,it puts forwards the driving factors including knowledge sharing cognition,technology gap, the economy and geography space, spill risk control and spill achievements’compensation.According to supply chain benefit coordination problem,it adds members’ participation and contribution factor for Shapley amendment model.Then it verifies rationality of the model by empirical analysis,which would be helpful for further knowledge spillovers benefit evaluation and compensation mechanism research.

Abstract: BCB(Bamboo Charcoal Bonded) grinding wheel is a new kind of grinding wheel developed by bamboo charcoal-phenolic resin composite for ELID(Electrolysis In-process Dressing) grinding technique. To study the affection of the ground workpiece surface roughness and removal rate with this new kind of grinding technique, the stainless steel SUS304 was ground using BCB grinding wheel in different machining parameters with ELID grinding condition, and the machining characteristics of BCB grinding wheel has been researched. The experimental results indicated that the ground workpiece surface roughness can be reached to Ra 0.010μm, and the efficient and precision machining with BCB grinding wheel by ELID grinding technique has been achieved for hard-to-cut materials. Finally, by studying of the grinding wheel surface condition and wear, the BCB grinding wheel grinding mechanism has been preliminary discussed.

Abstract: Thermal deformation is produced by heat sources in CNC machine tools. Thermal error is one of the main parts in CNC machining errors. The internal and external heat sources were introduced. The research status about thermal errors was analyzed, including identification of thermal sensitive points, precaution against thermal errors and error compensation. Finally, thermal error models were summarized and discussed.

Abstract: The principle of the friction stir processed (FSP) was studied in this paper. When the rotate-speed of the mixing head is 3000r/min, as feed speed of the mixing head is 15μm / s and cutting output is 0.1mm,an influence area constituted with Fe-Al intermetallic compounds was produced between the coating of high-speed steel and Al substrate because of dynamic recovery and recrystallization.The Fe-Al intermetallic compounds can improve microhardness as hard strengthening phase.and the highest microhardness of the influence area achieved 600 HV.

Abstract: On the basis of electroless Ni-P plating, the technique of electroless Ni-P-nanometer diamond composite plating for 2A12 aluminum alloy was studied. The table of L₉ (3⁴) of orthogonal design was adopted in the experiment. The optimal formulation of plating bath for 2A12 aluminum alloy was determined. The effect of bath composition on deposition rate and adhesion strength was studied. The results show that the order of marked factors on deposition rate from large to small is nanometer diamond, sodium acetate, nickel sulfate hexahydrate and sodium hypophosphite in turn, while for adhesion strength is nanometer diamond, sodium acetate, sodium hypophosphite and nickel sulfate hexahydrate. The optimal plating formulation are consisted of nanometer diamond (2g/L), NiSO4•6H2O (30g/L), NaH2PO2•H2O (30g/L) and CH3COONa (15g/L), which is operated at 80~85°C, pH (4.5). The microstructure of coating plated with optimal process is cellular structure, which is homogeneous, compact and good brightness, and its deposition rate is 17.0μm/h.

Abstract: With the development of auto industry, the cam quality requirements higher and higher. In order to illustrate the effect of servo lag upon cam Contour error, X-C servo axis Trajectory coordinates have been acquired in real-time with dual-channel mode during cam grinding. By comparing the Trajectory coordinates detected and the interpolation contour, the errors caused by servo feed lags were verified, and the mechanism that how axis feed acceleration impact on cam Contour errors was proposed. Based on data acquisition and product test, the error compensation method based on servo lag is proved reasonable.

Abstract: The non-cyanide silver electroplating on copper substrate has been discussed. Based on the surface morphology by using SEM, the smooth and fine silver layer is obtained. The influences of concentration of silver and plating temperature on the thickness of the plating layer are discussed, the thickness of the silver layer is increasing with silver concentration rising and plating temperature rising.

Abstract: A stage-structured predator-prey system with time delay is considered. By analyzing the characteristic equations, the local stability of a positive equilibrium and a boundary equilibrium is discussed, respectively. Furthermore, it is proved that the system undergoes a Hopf bifurcation at the positive equilibrium when . The estimation of the length of delay to preserve stability has also been calculated.

Abstract: The traditional method to remove zinc coating from matrix has some problems, such as complicated process, expensive cost, and environmental pollution problems. In our article, mechanical method is proposed to remove zinc from galvanized sheet. Using this method, In the paper, the galvanized sheet can reused by an easy and low-cost method. The paper mainly introduces the technological process, best choice of abrasive material and analysis of the results. Under laboratory conditions, this study has achieved some achievements, which has some guiding significance for removing abandoned tobacco zinc coating in future practical production.