Papers by Author: Gui Cheng Wang

Abstract: A finite element model was developed for simulation of two side direction burr formation process. Based on strain distribution, a two side burr formation mechanism was proposed. Burr form and burr size of simulation are close to that's of experiment. Finite element model generated here provided a numerical analysis method to solve the prediction of burr and chip formation and physical insight into the fundamental burr formation mechanism. The stain in two side direction of material near the side face decides the shape and the size of two side direction. Multi-workpieces are machined at the same time with side face closely by each others can control the formation of two side direction strain and two side direction burr.

Abstract: Large quantities of coolant-lubricants are still widely used in metal working industry, generating high consumption and discard costs and impacting the environment. An alternative to current practices is to use biodegradable cutting fluids that doesn’t pollute environment or require new setups. In current study, biodegradable base oils, synthetic ester and castor oil, are chosen and compounded into cutting fluids which correspond with the national standards. The tests have been performed to high speed turn AISI 1045 steel in ester-based fluid, castor-based emulsion, kerosene and dry condition. The results indicate that the application of cutting fluids is inevitable in metal machining and can not be replaced by dry machining. The lubricating and cooling properties of the ester-based fluid and castor-based emulsion are better than kerosene and can wholly replace mineral oil.

Abstract: One of the main problems in the process of micro-machining for small and precision parts is that micro-burr will be generated. This paper carried out the two-dimensional numerical simulations with ABAQUS, which simulated the effects on burr formation coming from the micro-burr formation mechanism, tool geometry and cutting parameters in micro-machining process. The general rules of various factors impacting on burr formation were obtained in micro-machining process.

Abstract: Based on analyzing the defects of the usual equivalent conversion methods,the paper presents a new equivalent conversion method for mesh stiffness calculation of straight bevel gears of the small teeth number and diameter. By means of comparison among the different calculation methods,the conclusions can be obtained as follow:The straight bevel gear’s mesh stiffness value calculated by the new equivalent conversion method and Yishikawa formulae improved is more enhanced obviously than one calculated by the usual equivalent conversion methods and Yishikawa formulae ,and its change trend is closer to the numerical calculation value than the change trend of the straight bevel gear’s mesh stiffness value calculated by the usual equivalent conversion methods and Yishikawa formulae.

Abstract: Vibration tapping is capable to tap the deep and small hole in difficult-to-machine materials. Taguchi method is utilized to optimize the parameters in vibration tapping process in order to get the lowest maximum torque. Besides these parameters, this investigation includes the lubrication conditions comprised of dry cutting, conventional flooded lubrication and minimum quantity lubrication (MQL). The results show that the frequency and lubrication condition are significant and interaction effects exist due to these two factors.

Abstract: To solve the problems caused by the cost of metal working fluids in manufacturing processes, many methods have been employed. MQL (minimum quantity lubrication) is a successful application as a green manufacture strategy. Vibration tapping is a workable tapping method with good performance. An application of MQL technique in vibration tapping was studied. Maximum torque and chip morphology were used to evaluate the performance of MQL operation. A comparison among MQL, flooded and dry operations was carried out. The results showed that MQL decreased the maximum torque value obviously and the chip morphology under this condition was good.

Abstract: s. The work principle of indexing mechanism with globoidal cam is depicted firstly. Equations of the contour surface and the conjugate contact line are deduced by rotating matrix operators. The value of roughness becomes very small by high speed machining, so it can replace the grinding. At last, kinematics analyze and motion simulation are carried out.

Abstract: In grinding hardening process, part’s surface (grinding zone) temperature directly affects the quality of surface layer of heat treatment. The high temperature heat pipe is very good device of control heat transfer. In order to make the grinding zone temperature slightly change in grinding process, this paper describes a design of temperature automatic control technology. A high temperature heat pipe contact with the part’s grinding zone. The zone temperature is measured using infrared radiation pyrometer and the temperature data will be used to control the high temperature heat pipe’s thermal resistance through the PID controller. That is that the PID controller will adjust the contact area between part and high temperature heat pipe, thus achieves control of part’s surface hardening requirements.

Abstract: Thermal stresses of grinding plays an important role on the fatigue and wear resistance of the component. A comprehensive analysis of thermal stress induced by surface grinding has been conducted with aid of the finite element method. To obtain a reliable figure of thermal stress induced by grinding, temperature-dependent properties of workpiece materials were taken into account. The developed finite element procedure has also been applied to calculate the surface and sub-surface thermal stress induced by moving source of triangular heat when convection and radiation is occurred over the whole work. Based on an analysis of the effects of wheel velocity on the thermal stress distributions in an elastic-plastic solid, some important conclusions were given.

Abstract: In metal processing, lubricant penetration process can be explained by the capillary model theory. Observed through microscope, cylindrical capillary model was chosen and was analyzed on the basis of hydrokinetics. Moreover, it was indicated of the basis for dividing the entire penetration process. Based on kinetic theory of gases, the penetration of gas-liquid two-phase flow in minimum quantity lubrication (MQL) machining was simply analyzed and it was pointed out that there was only gaseous phase filling process.