Advanced Materials Research Vol. 764

Abstract: The friction and wear properties of several common metal materials (45#, 25CrMn, and 40CrNiMo) friction pair under oil lubrication was investigated on M-200 Type wear tester, and studied the friction under the condition of differ sliding speed and pressure. The results show that: the 25CrMn/45# steel pair has better tribological and wear performance; the load is the main factor which influences the friction of the material at the low sliding speed; the main wear form is adhesive wear, but the wear mechanism is gradually became from adhesive wear to abrasive wear and flaking wear with the contact pressure and sliding speed increased.

Abstract: In this paper an experimental study in milling of SiCp/Al composites on a high precision machine was carried out by using TiN coated tools, TiAlN coated tools and carbide tools. The result of tool wear was observed and measured by an optical microscope and a scanning electron microscope (SEM). The results show that the main wear mode is the flank wear and the wear mechanism is abrasive wear and adhesive wear for the cutting tools used in the experiment.

Abstract: Tribological properties of ceramic cutting tool materials in contact with wood based materials were studied in this paper by examining how Al2O3-ceramics and Si3N4-ceramics behave in dry sliding experiment in contact with wood-based materials and by comparing their behavior with tungsten carbide material at the same time. It had been found that the ceramics exhibited much better tribological properties than tungsten carbide material, and Si3N4-ceramic performed better than Al2O3-ceramics. The Al2O3-ceramics with an addition of ZrO2 had better tribological performance than the common Al2O3-ceramics in contact with wood-based materials. The tungsten carbide had better tribological performance than ceramics in tribological contact with wood flour/PE material. A well-marked difference occurred in various cutting materials/MDF frictional pair, but the differences in various cutting materials/PB frictional pair were insignificant. An increase of the normal force didn’t result in any significant decrease of the friction coefficient. An addition of ZrO2 in the Al2O3-ceramics could inhabit corrosive wear.

Abstract: A new technique of aircraft structural health monitoring so-called Comparative Vacuum Monitoring (CVM) is introduced in this paper. Compared with the traditional and some novel Non-Destructive Testing (NDT) techniques, it is capable of real-time crack initiation and growth detection reliably and accurately, and especially suitable to monitor the interior locations with hard accessibility. With the advantages of this technique, the aircraft manufacturers (such as Boeing, Airbus, Bombardier, Embraer, ect.) are much interested in applying it into aircraft structural health monitoring and have carried out verification tests on aircrafts or technology ready for the future usage. Through the use of CVM technique, it is possible to quickly, routinely and remotely monitor the integrity of a structure in service.

Abstract: Aiming at the characteristic of bearings supported in rolling mill and combining contact mechanics and finite element method, the edge effects of the cylindrical roller bearings used in the rolling mill are analyzed based on FEA for the Roller system of Rolling Mill and FEA of the bearing whole. According to the results of three dimensions FEA on the edge effects, different modification curves are taken to design crowned profiles of the cylindrical roller bearings. And comparison between the effects of the different modification curves is done through the simulation of 3D FEA, so the guides are offered to optimize the cylindrical roller bearings used in the rolling mill.

Abstract: Study of predicting chatter has been around for many years. These studies are crucial for our understanding of machining processes and to enhance efficiency in manufacturing. This paper presents a new mechanism affecting the stability of machining process called mass induced damping. This effect is simulated numerically with tested values of initial parameters taken for impact tests of a thin-walled workpiece. Results from the simulation shows minor increment in allowable depth of cut by numerically calculated using stability lobe theory. This effect will open a new understanding how certain mechanical factors would affect the value of damping of a system.

Abstract: In this paper, the system architecture Integrated with cutting parameters database and process case database was proposed. Windows-based NC machining process query system was developed by using VB combined with access database, the system has turned the NC processing handbook into electronic handbook, at the same time, many real product process experiences was integrated in it, which effectively solved Electronic management of the NC machining process parameters and query. The employee can quickly accumulate experience by using the system and enrich their process acknowledge.

Abstract: The processing simulation method of numerical control electrochemical turning (NC-ECT) was presented based on the finite element method (FEM) in this paper. The three-dimensional analysis model of the electric field built in ANSYS software was solved. The current density distribution and the theoretical values of material removed depth per revolution (MRDPR) in different time on the anode were obtained. The experiments were carried out on the NC-ECT lathe, and the measured values of MRDPR were measured, which were compared with the theoretical values. It is indicated that the maximum percentage error between the theoretical values and the measured values is smaller and the simulation method meets the accuracy of the engineering calculations.

Abstract: A novel algorithm of space vector PWM (SVPWM) based on artificial neural network is proposed in this paper, in order to cope with the complex calculation required in Space Vector PWM. It makes full use of the fast parallel computation and learning capability of ANN to shorten the time of calculation and reduce the harmonic composition and loss. The simulation model of vector control for permanent magnet synchronous motor drive system is built and simulated in MATLAB/Simulink. The simulation results show that the permanent magnet synchronous motor drive system based on artificial neural network SVPWM has more perfect performance than that based on traditional SVPWM controller in dynamic and static property, such as little torque pulses as well as robustness.

Abstract: The bearing pre-tightening force on the guide of high speed punch press has immediately influenced the running accuracy of the slide, as well as the precision of the high speed punch press. So, the control of bearing pre-tightening force on the guide of high speed punch press was a very important issue in the study of high-speed presses. Through the research and analysis of the guidance system structure, the method of adjusting and controlling the guide rail bearing pre-tightening up force has been proposed in this article.