Applied Mechanics and Materials Vols. 670-671

Abstract: In order to improve the performance of end face grinding wheel, the phyllotaxis theory is introduced into the design of the wheel. Meanwhile the movement track equation of the end grinding is established, and the effects of the phyllotactic coefficient on the grinding surface roughness are studied. The simulation results show that the lower surface roughness values can be obtained when choosing reasonable phyllotactic coefficient. It will provide theoretical basis for the ordered abrasive patterns of the end grinding wheel.

Abstract: In order to analyze performance of the Capacitively Coupled Plasma (CCP) etcher, commercial software like OPTIMUS can be applied to approximate etch process model by Response Surface Method (RSM) or Radial Basis Functions (RBF). Multi-factor parameters are concerned in etch process, like frequencies of the dual Radio Frequency system (RF) and flow rate and flow ratio of the process gas. When facing the multi-dimensional problem, the algorithms would turned to be inefficiency and the optimization process may be trapped in local minimum area or cannot converge because of oscillation. To improve surrogate modeling for the CCP etcher, a self-optimizing RBF (SO-RBF) algorithm is proposed and a process modeling tool is developed. Experiments on a state-of-art dual station CCP etcher shows that based on the global approximation model generated by this algorithm, process parameter optimization can be easily implemented with less error than OPTIMUS.

Abstract: The characteristics in microstructure, surface morphology, chemical composition, hardness and wear resistance of the three protective iron-based compound coatings prepared by Supersonic Arc Spraying (HVAS), were investigated by X-ray diffraction (XRD), Field emission scanning electron microscope (FESEM), Energy disperse spectroscopy (EDS) and Rockwell apparatus in this paper. It is indicated that the three coatings are typical layer and compact structures. The coatings are composed of Fe (s.s) phase and various kinds of ferric oxides, chrome carbides and/or intermetallic phase distributing along the interface of lamellar layers. More Cr and Ti, Al elements in the cored wires can degrease the diameter and alternate the morphologies of the holes in the coating, resulting from the formation of oxides, carbides and intermetallic phase during depositing the coating. The results indicate the SXTiAlC coating shows the most excellent wear performance among the three coatings. The wear behavior and mechanism are discussed.

Abstract: Diamond-like carbon (DLC) films were prepared on the Si (100) substrates by pulsed cathodic arc plasma. The influences of given pulse frequency on the microstructure, morphology, mechanical and optical properties of DLC films were investigated by Raman spectroscopy, atomic force microscopy, Knoop sclerometer, X-ray double-crystal surface profilometer. The results showed that the variation of pulse frequency could significantly change the microstructure of DLC films, including the size and ordering of sp² carbon clusters and movement or diffusion of carbon atoms. The increasing of pulse frequency led to the variation of the relative fraction of Csp³/Csp². The hardness and internal stress of the DLC films were affected accordingly. The results might contribute to the synthesis of DLC films with excellent structure and properties by cathodic arc evaporation.

Abstract: rolling/plowing-extrusion is a new method for fabricating outside 3D integral fin stainless steel tube.The effect was investigated about Rolling and plowing-extrusion affect the finned forming and structure. In this study, the rolling depth and direction were analyzed. The results are shown that The rolling processing play an important role to finned structure.When the rolling depth is 1.5mm, and other parameters are reasonable by right spiral groove, the optimal fins were obtained.

Abstract: Experiments were preformed to investigate the effects of micro-arc oxidation coating technology, nitrification technology and plasma spray technology on Ti6Al4V alloy. The morphologies on both exterior and section of the processed surfaces were analyzed. Characteristics of treated layers like thickness, hardness, roughness and friction coefficient were also studied and compared. The results show that these technologies can improve the surface hardness and friction coefficient by different degree, but also will destroy the smoothness.

Abstract: The corrosion properties of friction stir welded 2024 aluminum alloys are studied in this paper. The results show that after 50 hours corrosion in 3.5% NaCl solution, the strength limit, Yield strength and elongations decreased compared to non-corrosion specimen, but not much. All fracture initiated at surface or sub-surface flaws at advancing side. Larger propagation zone is seen in corrosion specimen compared to non-corrosion.

Abstract: A shrouded turbine blisk is taken as the research object. Based on NURBS surface modeling theory and by using SolidWorks software, a 3D model of the blisk was gotten. An electrode was designed according to the characteristic of channel between two blades of the blisk. A set of fixtures for manufacturing the blisk was designed, which can realize measurement on-line. Computer simulation of manufacturing the blisk was conducted. The simulation results show that there is no interference between the blisk and the electrode. So the feasibility of manufacture is verified. The simulation results have provided an effective basis for the subsequent processing of the blisk.

Abstract: This paper is mainly to study the tensile and resilience performance in a knitted plain Modal fabric by uniaxial and biaxial experimental. The results indicated that under uniaxial tensile, the breaking strength along warp direction of the knitted plain Modal fabric was higher about 75% than the strength in weft, while weft elongation was higher about 60% than in warp. The strength-strain curves under uniaxial tensile and biaxial tensile of the fabric were made up of approximately three stages: a linear stage and two nonlinear stages. A set of parameters and a serial mathematical fitting model functions of the strength-strain curves were obtained by experimentally. It could be predicted stress and strain of knitted fabrics under some given certain elongation or load to meet certain clothing pressure comfort for underwear fabrics or garment.

Abstract: Application of coil diameter calculation is very important in the industrial field. The demanding for the precision of control is increasingly strict. There are three methods to achieve a higher precision. They are the Count-method, Linear /Angular Velocity and Distance Calculation respectively. In the process of coiling and uncoiling, advantages and disadvantages are existed. There are different requests for realization of the functions as well. In the Siemens PLC S7-300 control system, these three methods can be used to achieve a higher precision of coil diameter calculation and control. Different improvements and adjustments, according to methods, are given in the process of the test. Some algorithm has been optimized. Finally, by using the three algorithms, the dynamic change of roll diameter can be calculated and meet the need in the course of steel strip.