Papers by Author: Peng Zhang

Abstract: There are many inclined holes in modern manufacturing industry. Due to the special machining state of drilling out, the drilling jigs and other auxiliary mechods can not been used. There is intermittent cutting for a long time during drilling out, and the axial force and torque are also impact force, which cause the drill to break. The experiments results showed that the axial force and torque were also been incresed, especially the later, which is the principal factor of the drill fracture. So it is the experimental foundation for further to control and protect the dill to break.

Abstract: The nano-composite electroless coating was introduced into bio-limited forming technology for the first time, and the feasibility of the nano-composite electroless coating on microorganism was verified. The composite coated microorganism was analyzed by using optical microscopy, scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The results showed that stirring method would make significant effect on the content of nano-particles in the composite coating. And compared with mechanical stirring, the magnetical stirring makes the content of Fe in the composite coating increase almost twice. The co-deposition mechanism of the composite coating was also discussed.

Abstract: There are different opinions on whether the tool life could be improved by the vibration drilling or not. The factors which affect the drill life during micro hole drilling were analysed, and the vibration drilling has the effective region characteristic for drill life. That is to say, the vibration drilling can extend the tool life significantly within the certain range of the hole depth (or depth-diameter ratio). The stainless micro hole drilling experiments were done, and the results showed that the life advantage for vibration drilling was represented on certain region, that is effective region phenomenon

Abstract: Surface roughness in a turning operation is affected by a great number of factors. Two of the most important factors are feed rate and the size of the corner radius. Surface roughness can be roughly determined to increase with the square of the feed rate and decrease with increased size of the corner radius. However, wiper insert geometries changed this relationship with the capability to generate good surface roughness at relatively higher feeds by transferring small part of the round insert edges into the straight cutting edges of the pointed insert. The principle of how wiper inserts behave different from conventional inserts as to the effects on the surface roughness is explored in this paper. Experimental study of the surface roughness produced in the turning of hardened mild steels using coated carbide tools with both conventional and wiper inserts is conducted. The test results prove the effectiveness of the wiper inserts in providing excellent surface roughness. The results also suggest that the use of the wiper insert is an effective way that significantly increases cutting efficiency without changing the machined surface roughness in high feed turning operations.