Papers by Author: Jian Ming Zheng

Abstract: The graphite-like carbon (GLC) coating was deposited onto high-speed steel (HSS) twist drills by magnetron sputter ion plating technique. The drilling tests were performed on the ferrous metal under dry cutting conditions. By the analysis and comparison of the flank wear and the drilling forces on drills, the cutting performance of GLC coated HSS tools was researched. The results show that GLC coating with high hardness and low friction coefficient, due to its good adhesion and match with HSS substrate, can significantly improve the cutting performance of HSS twist drills, prolong the tool life, decrease the drilling forces in drilling the ferrous metal. And its cutting performance is better than the hard coated drills in the lower speed, but its thermal stability is inferior to the hard coated drills in the higher speed.

Abstract: The Shape from Shading (SFS) method is adopted to detect the micro-topography and roughness parameter of machining surface based on computer micro-vision in this paper. According to the reflection features of micro metal surface, the illumination model is improved by the weighting superposition of the diffuse component of the simplified Oren-Nayar model and the specular component of the Torrance-Sparrow model. The minimized calculation method of SFS is given based on the improved illumination model. The 3D topography reconstruction and the roughness parameter detection of the turning surface are accomplished. The experimental results show that this method can rapidly realize the accurate detection of surface roughness parameter, and provides new ideas and methods for detection the roughness on-line in machining process.

Abstract: In view of the inherent limitations of classical Hough transform in the detection of line, an improved algorithm of randomized Hough transform is offered in this paper. The feature point sets are segmented based on the connected component labels in this algorithm. The elements of various point sets are stored in sequence so as to reducing the invalid samples. By using a valid line detection area and a dynamic storage management, the temporary storage units are gradually reducing with the iterative process. The speed of the line detection and the accuracy of identification can be improved, the storage space can be reduced, the computational complexity can be cut down and some unnecessary calculations can be avoided by using this algorithm. However, it still has the characteristics of the classical Hough transform that it is not sensitive to noise. The line edge where the cutting tool is on can be pinpointed. To achieve the vision-based mode of tool wear state, it can accurately detect rake and flank face of the cutting tool, and can effectively remove the influence to the tool wear detection from the BUILT-UP EDGE in cutting process. By the validation of testing examples, the algorithm has high speed, low memory occupation and high accuracy.

Abstract: A novel rolling method based on the traditional plastic rolling principle is introduced to solve the problems in the plate-fin machining process in this paper, such as technological complexity, fin falling, high rate of rejection, high cost and so on. The finite element simulation models of the rolling tool and workpiece are established according to the plate-fin plastic rolling principle. The plate-fin rolling process is simulated with Deform-3D. The state of stress-strain and laws of metal flowing are studied. The plate-fin rolling experiments are carried out by using industrial purity aluminum AL-1100. The fin appearance and characteristic parameters are consistent with simulation results. At the same time, the experimental results verify the feasibility of plate-fin rolling forming method and the accuracy of the numerical simulation results.

Abstract: The cutting-press compound shaping technique is a green technology for manufacturing some functional surfaces such as fin-tubes. In practical application, different fin parameters and fin structures are required. Aiming to obtain different fin structures, the determination of the geometric parameters of the fins is discussed; according to the affects of the side cutting edge on the fin shapes, different fin structures under different side cutting edges are analyzed; which can provide guidance to obtain different fin structures under different applications.