Yun Ming Zhu

Formation and Simulation of Cutting-Direction Burr in Orthogonal Cutting

The cutting-direction burr is one of the important factors that influence the edge quality and performance of precision parts. The cutting-direction burr formation process is simulated with DeformTH3D. The mechanism of cutting-direction burr formation is analyzed in terms of the results of the simulation. The negative shear zone and initiation negative shear angle are discussed too. Study results show that the deformation of CDE is an important factor affect the cutting direction burrs’ size and shape.

Formation and Simulation of Two-Side Burr in Orthogonal Cutting

The two-side burr is one of the important factors that influence the edge quality and performance of precision parts. The two side-direction burr formation process is simulated with DeformTH3D. The mechanism of two-side burr formation is analyzed in terms of the results of the simulation. Enlarging the tool orthogonal rake and minimizing the depth of cut can reduce the burr size.

A Study on Burr Formation and Controlling Technology in Precision or Ultra-Precision Drilling

Burr formation is a common phenomena in metal cutting. The burr not only effect precision of parts directly but influence the assembly quality badly. Therefore, the control and deburring technology of machining burrs has become one of the key problem in precision or ultra-precision and automatic procession. In traditional drilling, the exit burr is bigger than the entrance burr, and its hazard is more larger. Moreover deburring process is very complex. According to these status quo, a new method of active control of the exit burr is put forward using vibration drilling. Mechanism of chip broken and burr formation in vibration drilling are analysed systematically and an equipment of vibration drilling is developed based on drilling experiment. Cutting test on A3 material, brass (H62) and 1Cr18Ni9Ti stainless steel is carried out using the method of vibration drilling. As a result, cutting character is improved because of the using of this method. Also, machining accuracy and surface integrality of parts are improved remarkably and the size of the exit burr is controlled effectively in vibration drilling. The development of vibration drilling device provides a new approach for the progress of ultra-precision drilling technology. Vibration drilling device and technology developed in this study can be widely used to ultra-precision machining.Copyright

Simulation of Two Side Direction Burr Formation

Two side direction burrs is an important factor of influence to edge quality and performance of precision parts. 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. Strain of Cutting lay material near the side face in two side direction of work piece is determinant factor of two side direction burr. 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 formation and physical insight into the fundamental burr formation mechanism.

Transformation of Cutting Burr/Fracture in High-Speed Machining Al Alloy

The metal cutting burr is one of the factors that influence the edge quality and performance of precision parts.A finite element model has been established to investigate the mechanism of burr formation and limit transformation in high-speed machining 2024Aluminum alloy .The burr/fracture formation process is simulated with elastic-plastic nonlinear element method based on ABAQUS.This paper has investigated the mechanism of burr /fracture formation and the limit transformation condition of cutting-direction burrs and fractures in high-speed machining and the limit transformation condition change with the cutting condition,which lay scientific basis of further research on cutting burrs formation and its minimization and deburring technology.

Formation and Control of Burr in Grind-Hardening

Based on grind-hardening experiments, the two side-direction burrs were studied. Three main stages (burr generation, augmentation and formation) in the burr yielding process were clarified and the varying laws of burr morphologies and dimensions were systematically revealed. In turn raises, some new technologies, processes and methods of actively controlling burrs were put forward.

Formation and Control of Two Side Direction Burr

Based on the orthogonal cutting experiments, the two side direction burrs in metal cutting were studied. In this study, the cutting model of two side direction burr formation and translation is established with plane stress-strain theory. The main laws of formation and change of burr in size and type in orthogonal cutting are revealed, and it is confirmed by experiment results, which first realizes control of the forming and change of the two side direction burr in metal cutting operation.

Characterization Method and Evaluation System of Surface Integrity in Precision Machining

The importance of the surface integrity in modern machining is represented. Based on the notion of the surface integrity that was put forward by Michael Field, a new method of surface integrity characterization is presented in this paper. This method consists of surface quality, surficial coat quality and the edge quality. Then an evaluation system of surface integrity based metrology is constructed and has been applied in a machining process of nickel-base alloy turbine disk. The manufacturing time decreased by approximately 10%. In all, this characterization and the evaluation system of surface integrity are rational and efficient. This work let us be capable of breaking through in the systematical evaluation of present machining surface.

The Development and Application of Expert System about Metal Cutting Burr Based on Neural Network

The formation of burr is a common phenomenon in metal cutting, its formation and variation directly affects processing quality and production efficiency of the workpiece. It is one of the key technologies which were applied in precision or super-precision manufacture and automatic processing. Burr expert system is not only a communication platform between burr formation mechanism and burr removal technology, but also an important channel that promote the development of burr-free cutting technology. It was highly concerned by mechanical engineering experts and scholars at home and abroad. This study develops neural network (NN) metal cutting burr expert system with network function, facing the application of burr removal technology, making use of neural network technology and expert knowledge system technology, and closely integrating experimental study of metal-cutting burr. Combined with milling, the study on prediction burr sizes using the system is carried out. The results show that the predicted results and the experimental results are in good agreement, which demonstrates the system is feasible and effective.

Active Control Methods of Cutting Burr in Precision and Ultra-Precision Machining

The burr formation and control is one key technology of achieving precision and ultra-precision machining and automatic machining. Based on the theory of system engineering, the metal cutting burr formation, control and removal technology system are constructed in the paper. Then, the basic principles of burr control are presented. Combined with precision and ultra-precision machining and automatic machining, the active control methods and technologies of burr are presented. They are the modified design of parts structure, the option of tool geometry parameters, the adjustment of cutting data and processing technologies optimization etc. So, these methods lay a solid foundation on achieving minimum burrs.