Papers by Author: Qi Long Yuan

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: Lead screw high-speed cold roll-beating is a new single-point incremental forming technology which is die-free and unconstrained. The principle of the forming process is analyzed. Modeling, meshing and parameter selecting for forming process simulation with ABAQUS are discussed. The lead screw cold roll-beating forming process simulation is carried out; stress & strain changes and metal flowing law are analyzed. Experiments are carried out with the self-developed experimental equipment. The experimental results are consistent with the simulation results, thus the validity of the simulation and feasibility of the forming process are verified.

Abstract: The high-speed cold roll-beating technology is adopted to realize the single-point accumulation forming of involute spline. Firstly, the principle of the forming technology is analyzed. Then the FEA model of the cold roll-beating of involute spline is built, the forming process simulation is finished with the ANSYS/LS-DYNA software to obtain the stress, strain and the metal flowing law of the forming process. Finally the experiments are carried out to verify the feasibility of the simulative results. This study can provide guidance for further study of the forming mechanism and practical application of the single-point accumulation forming technology.

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.