Abstract: Based on the analyzing ultraprecision grinding process of hard and brittle materials, taking ELID grinding of silicon nitride ceramic as an example, active control technology of passivating films state was introduced in this paper. ELID ultraprecision grinding process respectively at adaptive dynamic balance mode, discontinuous electrolyzing mode and discontinuous grinding mode had been comparatively studied. By means of AFM used for analyzing surface topography of parts, studies show that material removal method for ELID grinding is always a combination of micro brittle fracture, plastic shearing, lapping and polishing action, and which is the main material removal mode depends on the actual grinding contact state. Finally, finishing surface generating mechanism for silicon nitride in ELID ultraprecision grinding was summed up.
Abstract: Abstract: The article presents the optimized design of the strains transducer elastic component with double cantilever beam. The calculation has been made by the methods of differential equations in the mechanics of material and the finite element methods.We get the maximum strain range and the best gauge position of the strains transducer. The results by the finite element methods are in accordance with the one that calculated by the differential equations. The output sensitivity of the transducer has been analysed. The load electrical capacity output of the material testing machine has been calculated.
Abstract: In this paper, two processing techniques—full parameters technique and part parameters technique—for aspheric surface grinding are expatiated. Both of them are based on the priciple of computer-controlled optical surface (CCOS) and developed from trajectory forming method. We also have carried out appropriative software to digitalize processing technology. Proved by practical process, both of them are reliable and reproducible. Full parameters technique is easy to operate, but the accuracy of surface is to large extent dependent on the accuracy of measurement; Part parameters technique can avoid these measurements, however, it has certain requirements for operator. However, its requirements are still much less than those of traditional technique.
Abstract: Tool wear and failure monitoring has raised quite a lot of interests among researchers and has consequently been studied in a number of research projects by a number of research organisations. However, few researchers monitored tool wear in rotary ultrasonic machining (RUM) using various sensors. This paper, for the first time in literature, presents an experimental monitoring on tool wear in RUM of silicon carbide (SiC) using accelerometer, force and acoustic emission sensors. A digital microscope was used to observe the actual tool wear during the experiment. After describing the experimental procedures, it presents and discusses the results on tool wear and acceleration signal, force signal and acoustic signal in RUM of SiC
Abstract: Establish the three-dimensional finite element model of GSCK200A type High-speed & high-precision CNC Lathe spindle bearing, based on tribology and heat transfer theory, using ANSYS to analyze the corresponding temperature field and thermal deformation of spindle bearing in steady working state, according to this thermal deformation to obtain decrease volume of radial clearance, and the installation clearance optimization scheme is putted forward.
Abstract: In this paper, some problems in the polishing machine have been discussed, and a kind of ceramic polishing machine was designed. For improving the rigidity and stability of machine, we used closed style as the structure of spindle. And SYZ was used to make the stock removal homogeneous. By the performance test of polishing machine we can see that the change of removal was little, but the surface roughness by ceramic polishing machine was reduced more observably than the traditional machine. The results indicate that ceramic polishing machine can process high-precision ceramic products at the low cost to satisfy the needs of production and scientific research greatly.
Abstract: Common digital differential analyzer（DDA）linear interpolation error is lower than a pulse equivalent, and the output pulse along each axis is not uniform. New DDA linear interpolation flow chart was obtained by combining a quick algorithm of DDA interpolation and interpolating algorithm for pulses uniformization with common DDA linear interpolation principle. The relationship between interpolation error and pulse equivalent was demonstrated in detail. As the results shows, the new DDA with high precision machining but simple algorithm, increased interpolating speed; the new algorithm make the generation of uniform pulse series come true, which is of great importance to keep stepping motor rotating steadily without missing steps; At coordinate origin, interpolation error is lower than 0.42 pulse equivalent, while the interpolation point is not at coordinate origin, interpolation error is lower than 0.5 pulse equivalent.
Abstract: In this paper, a new procedure is proposed to study the deformation errors for spiral milling process of blade, which can be simplified as a stepwise beam based on the geometry and clamping characteristics. Kirchhoff beam theory is adopted to analyze the bending and torsion deformation. The relationship between machining deformation errors and the workpiece’s geometric dimension are also established based on the simplified model. Corresponding algorithms are realized by MATLAB codes. Experiment test shows that the results predicted by the proposed model are in well agreement with measured ones.
Abstract: In order to obtain the aims of weight reduction, efficiency increase and quality assurance of thin-walled parts of aircraft engine, the titanium alloy thin-walled parts are machined by precision machining method in the experiment. In this paper the precision machining method is used to cut titanium alloy thin-walled parts. The data of surface roughness is chosen as constraint conditions, and machining parameters will be optimized. The optimization parameters is feasible in this experiment, the optimization method is helpful to improve machining parameters and machining technology of titanium alloy thin-walled.
Abstract: This paper proposes the Gaussian Curvature by analyzing the free surface of the blade surface curvature, which is based on the Gaussian Curvature parameter mapping method to study the Gaussian curvature of free surface NC machining process interference. We introduce the conception of curvature to analyze the curvature and optimize the cutting parameter and cutting tool parameter to avoid interference phenomena happening and improve the processing efficiency and precision. Take the ball end cutter for example to process simulation, it shows that through the analysis of the free surface curvature method to avoid the intervention process is feasible, and has been verified by the experiment.