Papers by Keyword: Cutting Process

Abstract: The concept of multi-constrained analysis of the cutting process is presented for the first time in the paper. The paper adopts a method to solve an important problem which is how to judge the influence of constrains during the cutting process. The research results are applied for HSS drills for cutting stainless steel. On the basis of the multi-constrained analysis combined with methods of simulations and standard experiments, the optimum methods are provided for structure, coating and cutting parameters of cutting tools. For geometric structure of tools, optimization is to increase thickness of cutting and rake angle. Coating optimization strategy is choosing high temperature hardness and low thermal conductivity coating. Optimization of cutting parameter is to adjust feed fate, then select proper cutting speed. The conclusion of paper is helpful for the cutting optimization.

Abstract: The blade is a complex mechanical structure model which has two processing methods. One is making mold blade using the electrochemical methods and forming the blade molding using precision casting methods. But the cycle of this processing method is long and the process is complex and difficult to control. The second method is cutting the blade directly. The cutting force and the friction between tools and blanks can affect the machining accuracy of the machining. We should timely adjust the cutting parameters and cooling model to improve processing accuracy.

Abstract: In view of orthogonal cutting, finite element simulation geometry is built. the friction model, thermal conduction model and chip separation model are established between chip and tool using Abaqus which is a finite element analysis software. Through a specific example, two-dimensional finite element model have been established, simulating the cutting process stress distribution of the work piece surface is also obtained during processing. While simulation analyzes the relationship between the rake angle and shear angle, the results of simulation and experiment are basically the same, thus further verify the credibility of Abaqus simulation results on orthogonal cutting, and the feasible is also proved of obtaining cutting data by the use of Abaqus simulation cutting process.

Abstract: Processing in large numbers of small profiled parts shall be made usually on semiautomatic and automatic lathes. Outer turning with circular form tool and also drilling are the most common operations in such cases [. In a particular case, during tests in preparation stage of manufacturing technology, have found numerous unconformities and even accidents, reason for which also capability testing for those parts went out negative. There is thus a problem and she had solved: researching the causes of nonconformities and restore the quality and precision parameters of parts made. To solve this problem was commissioned a group of experts from the company, supervised also advised by two experienced researchers from a specialized institute. The research method used was the classical experimental processing established by a scientific program, the input data consisted of working parameters for outer turning with circular form tool (radial feed speed) and respectively drilling with a bit (speed and axial feed), and output data collected were the following: the main cutting force, the machined surface quality and the accuracy of dimensions of parts machined. The results obtained after the completion of experimental program were processed as graphs and charts and various observations collected over have undergone thorough analysis by specialists with great experience. Rigorous interpretation of the above results allowed the issuance of a series of recommendations on selecting the most appropriate working regime for turning and drilling respectively, and developing a written procedure to be followed to avoid future of such processing failures.

Abstract: Based on FEM, the paper presents a reasonable four teeth end mill model to simulate the process of metal milling, which uses the adaptive meshing criteria.This model simulates a typical work-piece chip breaking process with different cutting speed and feed ratio, which gets the cutting forces curves and the total status of residual stress distribution.

Abstract: Through research of stiletto and analysis of cutting process of manual thermite cutting technology, mechanism and chemical compositions of cutting ammunition is expounded. This type of cutting ammunition was only operated in terms of some cutting technology, including cut method, cutting technique parameter, cutting operate. The chemical composition of the cutting ammunition is the key to the final incision quality. The powders include thermite, gas-making agents and alloying addition. KNO₃ is up to 4.8% to 10.5% in the cutting medicament and CuO+Al is up to 13.6% to 22.8% in the thermite to cut steel of Q235 which is 263mm ×165mm × 20mm on the basis of the eject times of case primer, depth of the hole, diameter of the hole and the taper .

Abstract: Gear hobbing in cryogenic air with minimal quantity lubricant (MQL) is a better choice to take place of traditional gear hobbing in oily cutting fluid, in which cryogenic air with pulverized vegetable oil place the great amount of mineral cooling oil, to play the role of lubrication, cooling, chip clearance, and rust prevention. By the comparative experiments, differences on cutter wear are explored, among cryogenic gear hobbing with MQL, gear hobbing in oily cutting fluid, and dry gear hobbing. It indicates that the gear hobbing in cryogenic air with minimal quantity lubricant is practical, and not only a great amount of cooling oil is saved to lower cost and environment pollution, but also life-saving of hobbing cutter reduces production cost.

Abstract: The objective of the present work is to study tribological properties of multilayered wear resistant coatings on the cutting tools. Two types of coatings (TiAl)N were studied: normal monolayer coating and improved coating. The tests were conducted with cooling, and without it. During high speed machining an intensive tribo-oxidation of tool surface occurs. Formation of aluminum oxide films on the surface of cutting tool significantly changes the heat flow and heat dissipation into the chip. Conditions of the chips formation (chip thickness ratio and the shear plane angle) and the coefficient of friction on the rake face of the cutting tool have been measured during the cutting process. The results demonstrated significant improvement of tribological parameters for the cutting tools with filtered coatings.

Abstract: A new approach using Hurst exponent extracted from the texture of cutting surface was proposed to characterize the nature of the observable long-term-memory power system function of cutting process. Hurst exponent extraction algorithm was given. The cutting images were gotten from the experiment of tool wear monitoring system. Then the Hurst exponent is extracted from the images during the cutting process. Experiments show that the reduction of Hurst exponent reflected the tool wear process and the Hurst exponent can be a monitoring feature.

Abstract: By kinematics and dynamics analysis of the separate elliptic ultrasonic vibration cutting process, the mechanism of elliptic ultrasonic vibration on cutting process is revealed, and the physical essence of improving the stability of cutting process is clarified.