Advanced Materials Research Vols. 690-693

Abstract: This work presents an experiment research on Acoustic emission (AE) signal and the surface roughness of cylindrical plunge grinding with the different infeed time. The changed infeed time of grinding process is researched as an important parameter to compare AE signals and surface roughnesses with the different infeed time in the grinding process. The experiment results show the AE signal is increased by the increased feed rate. In the infeed period of the grinding process, the surface roughness is increased at first, and then is decreased.

Abstract: The titanium alloy Ti-1023 is widely used in aerospace industry, because of its low density, high strength, good corrosion resistance, etc. the integrity of the parts’ milling surfaces is of critical importance for aerospace industry. This paper aims to study the influence of the cutting speed and tool flank wear on hardness and hardening depth. The result shows that hardness and hardening depth have a significant effect on the cutting speed and the increasing of tool flank wear.

Abstract: The theory of grey systems has been used for performance prediction, relational analysis and decision making in many areas. In this paper, the grey relational analysis is applied to optimize the stainless steel cylindrical grinding parameters, and the corresponding grinding parameters are considered, such as spindle speed, feedrate, radial depth of grinding and workpiece speed. An orthogonal array was used for experiments design, and the surface roughness and the roundness were valued in the experiments. By analyzing the grey relational grade matrix, the most influential parameters could be selected. The results of confirmation experiments indicate that grey relational analysis can effectively acquire the optimal combination of grinding parameters.

Abstract: The purpose of this paper is achieve machining the equal base circle bevel gear with a disc cutter. Based on the equal base circle bevel gear theory, By solving coordinate values of the disk cutter section, made tool model in VERICUT environment. By planning disc cutter machining path , the disc cutter trajectory is obtained, simulated the NC machining to a equal base circle bevel gear using VERICUT software. The results show that machining this gear in NC machine can be realized using disk cutter.

Abstract: This paper analyzes the reasons that lead to edge failure on back-up roll and puts forward the countermeasures. The corresponding mathematical model of present grinding curve is designed, in order to adapt reconstructed roll.

Abstract: Elliptical vibration cutting (EVC) is one of the main methods to use diamond tool machining of hard to cutmaterial. Accurate prediction of cutting force in elliptical vibration cutting process is not only an important basis to properly choose of cutting parameters and optimal tool geometry parameters, but also a key factor to improve the processing property of cutting. A method to build cutting force theory model in EVC is presented in this paper. Eigen decomposition of the elliptic motion locus first ,then getting the piecewise function of the cutting force model. Based on simulation analysis of the cutting force model, this paper predict the rules that vibration amplitude and angle of tool geometry affect on cutting force, which provide theory basis for choose cutting parameters and cutting tool parameter in EVC.

Abstract: Ultrasonic vibration machining is a kind of effective method for precision processing of brittle-hard materials, especially it can obtain good surface quality in engine cylinder liner precision processing with the power ultrasonic honing. Based on the material removal mechanism of ultrasonic honing, a new ultrasonic honing force model was established, which included material chip deformation and friction situation between grains and workpiece. Therefore the effect to honing force can be known clearly with processing parameters and material physical change, which provided theory foundation to further study in ultrasonic mechanism and real time surface quality protection in honing process.

Abstract: Electrochemical mechanical machining (ECMM) is introduced to the manufacture of bearing crown roller-raceway in consideration of the very problems appearing in traditional machining methods. Firstly, numerical model on the non-uniform interelectrode gap ECMM is established and anode crown shapes under different cathode shapes are analyzed. Afterwards, according to the requirement of anode crown related cathode shape is formed through numerical simulation. In the end, the crown of bearing roller-raceway is machined by practical concave cathode with improved surface quality and certain crown face.

Abstract: The select of cutting parameters is not only directly related to the productivity, but also related to the change of cutting forces. Axial cutting force is too large to be ignored in the helical milling process. In this paper, the axial forces in helical milling of Cold die steel under different cutting parameters are measured, and the regression model of the axial force about the change of the cutting parameters is established, the influence of the cutting parameters on the axial cutting force is analyzed through the experimental results and the regression models respectively. The main purpose is to control axial cutting force and improve tool life in the cutting process.

Abstract: Rock tunnel boring machine is one of the main machineries and equipments for underground engineering, and the failure of tool systems is its main failure form. Rock hob test-bed is the only testing equipment for tool failure and wear. In this paper, the breaking rock by the double disc cutter is simulated and four kinds of rocks are selected to test the influece of rock characteristics and spacing between two disc cutters on the rock breaking by the double disc cutter test-bed. The results show that there is different optimal spacing between two disc cutters for different rock; the optimal spacing is inversely proportional to the hardness of the rocks; the maximum stress appears the boundary between the disc cutter and rock.