Papers by Author: Ya Dong Gong

Abstract: The process of micro-grinding on hard brittle glass is shown in this paper, micro-grinding equipments are designed by tools of electroplated diamond, fz(feed rate), ap (grinding depth), vg(Grinding speed) in micro-grinding brittle materials and their effects to surface quality have been discussed. It has been demonstrated that low surface roughness could be achieved by high vg and low fz. The roughness of Soda-lime glass accomplished by fz:100μm/s, ap:30μm, vg:120000rpm in the experiment is about 78nm.

Abstract: This paper presents a novel micro machining process that micro mill-grinding by combining micro-grinding and micro-milling. The principle of micro mill-grinding has been analyzed and a experiment is designed to study the influences in micro mill-grinding process on Al 6061-T6. The manufacturing is carried out on a desktop micro machine developed by NEU. In this research, analysis from results could found that the surface quality influences in micro mill-grinding is complicated affected both by milling and grinding, and conclude aspects such as cutter diameter, feed rate and material properties.

Abstract: This paper presents a novel micro shaft grinding tool is fabricated by cold sprayed with CBN grains, and a micro-grinding experiment is carried out to study micro grinding principle of the fabricated tools. The manufacturing is carried out on a desktop micro machine developed by NEU. Influences caused by particle size on surface quality has been discussed, it has been tested that low surface roughness could be achieved on 3000 particle size of micro shaft grinding tool, the roughness accomplished in the experiment is about 0.086μm.

Abstract: Through design of balancing movement controller of large size workpiece for applying to LDMC-100 type ion nitriding furnace, the structure and principle of mechanism were introduced, the balance of mechanical transmission and influencing to nitriding layer of workpiece surface were analysed. In this mechanism, the planetary gear system was adopted, the single axis was adopted in this supporting mechanism, and the electric and insulating on workpieces were used. The balancing influencing of movement and techniques parameters for nitriding layer were discussed. The results indicate, the nitriding period is related with input speed and number of driven gear teeth. The re-nitriding rate and blank nitriding rate are related with gear modulus, workpiece outside diameter, number of drive and driven gear teeth. When the mechanism structure parameter is fixed, the effect of nitriding was completed by changing speed of input axis.

Abstract: On-machine measurement and statistical analysis of wheel topography are important for real-time monitoring the wheel condition during grinding and predicting the performance of grinding process. In this paper, the surface topographies of grinding wheel in the different stages of the grinding of fused silica and BK7weremeasured with a white light interferometer, which was set on the surface grinder. Height parameters of 3D surface roughness were proposed to evaluate the wheel wear. Wheel wear mechanisms were essentially determined by analyzing the different material removal modes of optical glasses. Grinding of BK7 mainly causes severe attritious wear of grains, while grinding fused silica, self-sharpening effect makes grinding sustain for a long time.

Abstract: This paper presents a micro-grinding experiment on AISI 1020 steel to study micro grinding principle. A novel micro shaft grinding tool is fabricated by cold sprayed with CBN grains, the manufacturing is carried out on a desktop micro machine developed by NEU. Influences caused by particle size on surface quality has been discussed, it has been tested that low surface roughness could be achieved on 3000 particle size of micro shaft grinding tool, the roughness of AISI 1020 steel accomplished in the experiment is about 0.086 μm.

Abstract: This paper presents mechanisms studies of micro scale milling operation focusing on micro cutter edge radius. To address this issue, the tool wear model is developed in the present work. Starting with an analysis of the milling edge radius of the tool, the influence of the downscaling on the edge radius is determined by analyzing the milling force. This simulation is used to predict the extent of tool wear in the same milling operation condition by increasing of the tool edge radius. This model accurately predicted the increasing of force with tool wear progress and provides the means for further study of the micro milling tool wear.

Abstract: This paper presents a novel model of lay out of cutter head of TBM(tunnel boring machine). Rock-broken mechanism during the operation of the cutter head is analyzed to study the layout of cutters. A model of the cutters under the action of forces during TBM’s working has therefore been developed, thus proposing a scheme to improve the rock breakability of TBM’s cutter head on which the cutters are lay out. Then, a nonlinear multi-objective mathematical model with complex constraints is developed, with an optimization program provided via an intelligent algorithm for the layout design of cutters on the cutter head of a TBM. The cutter head of an EPB6.28 TBM, an optimized design is given to set up a prototype with digitized cutter head, to which a simulation is done for the verification of equilibrium of forces. Comparing analytically the cutter wear and equilibrium of forces between a previous and a newly designed cutter heads, the results shows digitally that the new one is more practicable than the previous one.

Abstract: The grind test is detected curve of the grinding surface roughness of cylindrical in use of three-dimensional contour in this paper, major influence factor in the accuracy of surface roughness is proposed in the analysis based on the chatter.

Abstract: The grind test is detected curve of the grinding surface roughness of thin in use of three-dimensional contour in this paper, major influence factor in the accuracy of surface roughness is proposed in the analysis based on grinding surface roughness.Trend of the grinding surface roughness is simulated in Matlab. It is expected that best surface roughness can be obtained by selecting the appropriate cutting speed and feed rate for the material pair of workpiece and cutting tool.