Key Engineering Materials Vol. 499

Abstract: Quick-point grinding technology, suitable to be applied in automobile manufacturing, cemented carbide and ceramic material processing industry, was an advanced ultra-high-speed grinding technology. It is the integration of super-high speed grinding, CBN super-abrasive and CNC flexible manufacturing and so on. The characteristics of quick-point grinding were systematically illustrated. Applications of this technology to process hard-machining materials and shaft parts were also given in this paper. Some problems and solutions corresponding to quick-point grinding technology were presented finally.

Abstract: By using ANSYS, the temperature distribution in workpiece of steel 48MnV under the actions of a moving thermal source, is first carried out by FEM for non-linear transient temperature field. On this basis, the residual stress distribution in the workpiece under the action of temperature variation and moving grinding loads is determined by FEM for thermo elastic-plasticity. The result shows that the existent residual stress on surface of grinding hardening is press. The reason of this is discussed. The difference between the simulated value and measured value of grind-hardening stress is acceptable.

Abstract: In micro-cutting process, it is very significant to study the variations of cutting forces and the factors affecting the forces for determining the machining parameters and for improving the performance of machining systems. The remarkable characteristic of micro-Cutting is that cutting parameters level closing to the crystal grain msize of material. Though, the prediction formula of micro-cutting forces should reference to strain gradient plasticity theory in formula construction, while cutting edge radius had been regard as a important parameters in the process of micro-cutting. The study show that, strain gradient reaction will be decreased by feed rate’s reducing in process, approximate expression of the strain gradient by the derivative of chip deformation rate, and the micro-cutting forces include hear flow stress, tensile flow stress ,and the friction force of rake surface.

Abstract: The technology of hard whirling is a kind of advanced manufacturing technology which integrates high efficiency, high precision and energy saving as a whole and attracts wide attention in machining field around home and abroad. Through studying on experiment of hard whirling machining on rolling bearing steel which has average hardness at 63.5HRC, this article focuses on different understanding of saw-tooth chips, illustrates the essential difference between macro- morphology and micro-morphology of saw-tooth chips, analyzes macro- morphology of saw-tooth chips with their corresponding machining parameters and finally raises a new solution to implement online monitoring on hard whirling machining.

Abstract: The force model of gun drill was put forward. It was found that the torque was sensitive to wear and carried the information of the status of wear stage. Moreover, friction between wear pad and work piece was the main source of torque. The experiment applied in studying the correlation between torque and wear has been performed on gun drill with and without TiAlN coating for machining steel S48CSiV with minimum quantity lubrication (MQL). The torque was increasing responding to the increasing wear of gun drill. The TiAlN coating delayed the wear rate and decreased the torque in the initial wear and gradual wear stage of the coated gun drill. The spallation of coating always led to the premature failure of coated gun drill and the spallation appeared if the rubbing and sliding force generated in the interface between the wear pad and the newly surface of work piece after drilling obtained a higher value than the coating’s adhered strength to carbide substrate materials.

Abstract: Orthogonal experiments of milling titanium alloy TA12 were done on the lifting workbench milling machine. The milling force signals were acquired through PIC-1712 Data Acquired Board. The main frequencies and energy distribution were got through analysis in SPTOOL of MATLAB. The signals were decomposed and reconstructed based on the main frequency of the milling force with wavelet toolbox. The influence of the milling velocity, axial depth of cut and radial depth of cut on the component milling force was got through range analysis. Through analyzing known that three factors had different influence on the component milling force.

Abstract: The operation simulation of wastewater treatment device based on swirling cavitation degradation has been done by means of CFD software. The condition of swirling cavitation formation and the shape of cavitation distribution were analyzed. The validity of simulation and wastewater treatment device operation were verified according to the testing results of device’s working parameters and degradation for Rhodamine B. The criterion to judge cavitation formation or degradation efficiency has been established. The industrialized enlargement for mini wastewater treatment device has been analyzed by means of simulation. It is useful to establish industrial application foundation of this kind of wastewater treatment device.

Abstract: The energy issue has been the focus of world’s attention. Wind plays a crucial role in the development and application of new energy as a renewable and clean energy. Wind turbine is the core component of the wind power system. It usually can be divided into horizontal axis wind turbine (HAWT) and vertical axis wind turbine (VAWT) by the relative position of the spindle and the ground. This paper analyzes the advantages and disadvantages of VAWT and summarizes the improvement of the VAWT from the energy congregating technology and self-starting technology which can provide technical support for the research of VAWT in the future.

Abstract: The paper focused on the effect of tool edge preparation of indexable carbide insert on cutting temperature, force and tool wear. The initial wear experiments were carried out to measure flank wear and two criteria to evaluate the effect of tool edge preparation were proposed. The cutting temperature measurement utilized tool-work thermocouple and revealed that the cutting temperature of honed insert was lower. The cutting force measurement with a strain gauge dynamometer showed that tangential cutting force Fz, feed force Fx would be increased and radius force Fy would be decreased after tool edge preparation.

Abstract: In the present study, an experimental investigation has been carried out in an attempt to monitor tool wear progress in turning Inconel 718 with coated carbide inserts under the wet cutting condition. First, each experimental test was conducted with a new cutting edge and the turning process was stopped at a certain interval of time. Secondly, the indexable insert was removed from the tool holder and the flank wear of the insert was measured using a three-dimensional digital microscopy (VHX-600E); and then the insert was clamped into the tool holder for the next turning experiment. The final failure of tool wear surfaces were examined under a scanning electron microscope (SEM) equipped with an energy dispersive X-ray spectrometer (EDS). It is indicated that significant flank wear was the predominant failure mode, and the abrasive, adhesive and oxidation wear were the most dominant wear mechanisms which directly control the deterioration and final failure of the cutting tools.