Advanced Materials Research Vol. 381

Abstract: Formulae of stress re-distribution and distortion by stress releasing during milling process are deduced to Initial Residual Stresses. Theory prediction of milling deformation due to residual stress is finished, and some calculating equation is given for the deformation solution. By means of these researches, the mechanism of the milling deformation due to residual stress is analyzed, the machining distortion caused by residual stress are analyzed and summarized using the analytical method.

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: 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: 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: 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: 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: This paper investigates the interfacial slip between the forming tool and workpiece in a relatively new metal forming process, cross-wedge rolling. Based on the finite elements method, three-dimensional mechanical model of cross wedge rolling process has been developed. Examples of numerical simulation for strain, stress distributions and rolling load components have been included. The main advantages of the finite element method are: the capability of obtaining detailed solutions of the mechanics in a deforming body, namely, stresses, shapes, strains or contact pressure distributions; and the computer codes, can be used for a large variety of problems by simply changing the input data.

Abstract: Toolholder radial rigidity plays an important role in tool vibration and the quality of machine face. Toolhoder radial rigidity is investigated by the finite element method. The factors such as the fitness between tool and toolhoder, the length of oil chamber bulge, oil pressure and rotation speeds are analyzed in the paper, the results can offer some effectively guidelines and reference for toolhoder machining and processing quality control.

Abstract: According to the simulation of the face gear in UG, the research established the model of face gear. A perfect model that can be used in ANSYS was obtained through reserve modeling. The blending situation of three models of face gear was analyzed in ANSYS. The blending stresses distribution area and the influence on gear teeth bending stresses of different parameters i.e. modulus, width and number of teeth were discussed. And the discipline of the bending stresses under these parameters was got. It provides a new analysis method to research the characteristics of stress of face gear.

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.