Papers by Author: Ai Bing Yu

Abstract: Having an automated nondestructive test of shells can improve their missile body’s defectiveness identification ability and ensure the manufacturing quality of the weapons and equipment. The CCD flaw detection system of the shell exterior surface is designed by using magnetic particle testing and CCD sensors and by using the feature extraction algorithm an image processing software is programmed and system simulation is carried out. The comparative study results showed that the system has avoided the manual detection error and omissions and the detection accuracy, detection speed and anti-interference capability was obviously improved.

Abstract: The materials removal rate (V/VB) was selected to be objective function. It is comprehensive parameter about materials and tools wear. Through turning glass ceramics experimentation, the materials removal influence of cutting speed, cutting depth and feed speed were study. Based on least square method, the multiple regression prediction model of materials removal rate was built. And the model was tested. It was applied to predictive and control. The results indicated: this model was well to express materials removal law in turning glass ceramics. The multiple regression prediction model is high remarkable. The prediction value was coincident with measure value. This model is high reliability. So, expect materials removal rate can been obtained by this model, and choosing the technological parameter can been guided.

Abstract: A novel algorithm of analyzing the textural features of image is put forward for color difference classify of ceramic tiles. First the image of tile is pretreated. Then two level wavelet decompositions are used on the image, and the energy feature of each sub-graph is extracted. The energy contains color and textural features of image, which be used to classify tiles into different color. Tile under test is classified according to the similarity measurement, which is the similar distance between feature value of tiles under test and the one of standard tiles. Euclid distance is used as similarity algorithm. Experimental results show that this method can reflect spatial relationship of color more effectively, and improves the accuracy of the classification in the production line.

Abstract: Edge preparation is a process to modify edge geometry and surface integrity of cutting tools. Edge preparation experiments of tungsten carbide cutting tools were carried out through an abrasive nylon brushing method. Tools wear and cutting temperatures with different edge radius were simulated with FEM software. The experimental results show that cutting edge defects were eliminated through brushing edge preparation. The edge radius has influences on cutting tool performance. When the edge radius is 20μm, the least wear can be obtained. Then tool wear value increases with the edge radius. A suitable edge radius will have a reasonable cutting temperature distribution. The tool temperature distribution shows the same results as tool wear. A suitable edge radius range is needed for edge preparation and a reasonable edge radius is needed to improve tool life.

Abstract: In order to improve cutting tool wear resistance, non-smooth surface was applied on HSS cutting tool and finite element method was used to analyze the wear of non-smooth surface HSS cutting tools. The orthogonal simulation test was established to analyze the influence of parameters on tool wear and the relationship between parameters and tool wear was discussed. Simulation results show that non-smooth surface could significantly improve the wear resistance of cutting tool. The line space has the most influence on cutting tool wear. The ranking of parameter influence on tool wear are line spacing, pit diameter and column spacing. And the lower tool wear usually occurs at points of pit line space which is three times as pit diameter.

Abstract: Regrinding of wasted cutting tools can recycle resources and decrease manufacturing costs. Influence of relative tool sharpness and tool cutting edge angle on tool edge radius were analyzed. Cutting force and cutting temperature were simulated with FEM on different edge radius. Edge preparation experiments were carried out though an abrasive nylon brushing method. The results show that RTS and cutting edge angle have influence on edge radius. Small edge radius might result in small cutting forces and lower average temperatures, could maintain the cutting state between tool and workpiece. The cutting edge defects can be eliminated through edge preparation, and a smooth cutting edge can be obtained. Cutting tool life will be improved through proper edge design and edge preparation.

Abstract: When diamond abrasive layer becomes thinner, remaining expensive diamond grits will lose their cutting ability. The recovery of waste diamond tools can realize the recycling of material, is one kind of green manufacturing. Taken electroplated diamond tools for example, key technical problems for diamond tool recovery were discussed in this study. A thermal shock method was proposed for electroplated diamond tools recycling processes. Based on heat elastic-plastic theory, the stress state between abrasive layer and substrate of electroplated diamond tools was analyzed. Thermal shock processes of electroplated diamond tools were simulated with finite element method. Thermal shock experiments of electroplated diamond tools were carried out with experimental electric furnace. The results indicate that there exists stress variation between abrasive layer and tool substrate interface during thermal shock operation. The stress change will result in the interface cracking and the peeling of abrasive layers from substrate. There exists obvious stress gradient between abrasive layer and substrate interface. The stress extreme value occurs on the area of abrasive layer transition region, the corner or end of abrasive layer. Experimental results prove that the separating of abrasive layer and the tool substrate using thermal shock method is feasible.

Abstract: Electroplating experiments were carried out using a conventional Watts bath with the application of ultrasonic in order to improve the coating quality. The effects of ultrasonic power on coating comprehensive characteristics were studied. The microstructure, hardness and thickness of the coatings were observed and determined by a HXD-100TMC type microhardness tester. The coating corrosion resistance was examined through soaking in 36% hydrochloric acid. The adhesive strength of the coatings was tested with the method of heat-shock. The results showed that the properties of the coatings are improved basically with the increase of ultrasonic power. It’s considered the coatings have the best comprehensive performances when ultrasonic power is 200W, which provides a basis for the subsequent fabrication of ultrasonic electroplated diamond tools.

Abstract: Tool edge radius has obvious influences on micro-cutting process. It considers the ratio of the cutting edge radius and the uncut chip thickness as the relative tool sharpness (RST). FEM simulations of orthogonal cutting processes were studied with dynamics explicit ALE method. AISI 1045 steel was chosen for workpiece, and cemented carbide was chosen for cutting tool. Sixteen cutting edges with different RTS values were chosen for analysis. Cutting forces and temperature distributions were calculated for carbide cutting tools with these RTS values. Cutting edge with a small RTS obtains large cutting forces. Ploughing force tend to sharply increase when the RTS of the cutting edge is small. Cutting edge with a reasonable RTS reduces the heat generation and presents reasonable temperature distributions, which is beneficial to cutting life. The force and temperature distributions demonstrate that there is a reasonable RTS range for the cutting edge.

Abstract: The single factor experience of Fiber Reinforced Ceramic Matrix Composites (briefly named FCC) grinding was done on a NC optical curve grinding machine, and then the morphologie of the grinding surface was observed with an optical microscope. The effect of the grinding parameters, which include mainly grinding depth, abrasive grain size of diamond grinding wheel and grinding direction, on the grinding-induced surface damage of FCC was discussed, finally, the paper drew the conclusions that both increasing of grinding depth and increasing of abrasive grain sizes of diamond wheel can make the grinding-induced surface damage worse, and that different grinding directions also produce different effects on the grinding-induced surface damage.