Abstract: For the abrasion phenomenon of the turbine flowing-passage components was very serious, the electrical discharge machining (EDM) surface strengthening process of stainless steel 1Cr13 by different electrodes were carried out in this paper, the formation laws and influencing factors of the EDM surface strengthening layer are researched deeply. The correspondence relation between strengthening layer thickness and enhancing time, electrode materials, and electrical parameters are obtained by the detailed theoretical analysis and experimental investigation. The results show that, in the premise of the strengthening layer thickness, workpiece quality and machining efficiency, the strengthening process can be improved by reasonable selecting and controlling the process parameters such as discharge voltage, capacitance, pulse frequency, peak current, pulse width and enhancing time.
Abstract: On the base of studying the forming mechanism of self-excited vibration and helix lobes in deep-hole boring, the paper established a mechanical model and analysed the effect of the length of the guide pads on the vibration and stability. Moreover, the reasonable length of the guide pads was verified by the experiments of the guide pads testing.
Abstract: A finite element heat transfer model incorporating a moving heat source has been developed to predict the temperature field in traverse cylindrical grinding. The model was then applied to analyse the grinding-hardening of quenchable steel 1045. It was found that in the region where the grinding wheel had an entire contact with the workpiece, material would experience a heating-cooling cycle, enabling the generation of a uniform hardened layer. In the transient regions at the two ends of the workpiece where the wheel-workpiece contacts were partial, the material was not hardened but experienced an annealing process. The results were in good agreement with the experimental observations.
Abstract: The grinding fluid has the function of cooling and lubricating only when it breaks through the airflow barrier near the grinding wheel and enters into the contact area between the grinding wheel and the workpiece. The air-fluid two-phase flow software is used to simulate the characteristics of the grinding fluid field based on VOF, and the special constraint conditions of the outlet pressure are not applied in simulation. The characteristics of the grinding fluid jet and the real moving characteristics of the grinding fluid between the jet flow area and the grinding area are analyzed. It provides the research foundation for the parameters of the grinding fluid supplying.
Abstract: Trying to analysis the influence of the instability of carbide tool materials on cutting temperature measurement by natural thermocouples, a series of experiments calibrating the thermal emf properties of tool inserts were carried out with an improved tool-workpiece thermocouple calibration device. Four chosen types of carbide tools were examined to detect their thermal emf on their different cutting edge areas. By calculating and comparing the thermal emf waving range of them, the thermal emf stability of carbide tools and the temperature measurement error lead by it was evaluated. As the experiments result, the influence was confirmed. The thermal emf variation among the cemented carbide tools was detailed by using certain statistics processing to the experiment data.
Abstract: Base on the conventional twist drill, the new type of solid carbide twist drill which the length-to-diameter radio (L/D) is about 12 was developed with improved parameters of drill point and flute geometry. Study of intensity and rigidity of drill was performed by using analysis software ANSYS Workbench for the theoretical support and technical guidance for the design of twist drill. Tests were carried out to compare the new drills with the competitive drills in terms of tool life, chip breaking, and chip disposal. The results obtained from tests indicated that the new type twist drills have similar cutting capability compare to the competitor’s drills.
Abstract: The invariable heat flux is always loaded in temperature simulation for grind-hardening. The heat flux is time-variant in actual process. The paper uses experiment result of grinding force to calculate out the time variation heat flux. The grinding temperature is simulated based on time variation heat flux by ANSYS software. The variation tendencies for the grinding force and the simulated surface top temperature will be discussed.
Abstract: 2D finite element modeling of the broaching process of Inconel718 was conducted by using the commercial software. Models between cutting forces and cutting parameters were obtained. In addition, a general understanding of the effects of two machining variables rake angle and rising per tooth on chip curling process and gullet-to-chip area ratio, was also obtained.
Abstract: A new planarization grinding method based on the cluster magnetorheological (MR) effect is presented to grind optical glass in this paper. Some process experiments were conducted to reveal the influence of the speed of the grinding disc and grinding time and grinding pressure during the machining process. The results indicate that the speed of the grinding disc influences definitively on grinding effect of this planarization grinding method based on the cluster MR-effect. When the speed of the grinding disc is 110r/min, better machining effect can be achieved. Furthermore, the influence of the grinding time on machining effect is obviously, and the proper machining time is 6mins. However, under the experiment condition in this paper, the influence of grinding pressure on machining effect is unobvious.