Papers by Keyword: Metal Cutting

Abstract: The article considers experimental studies of plastic deformation in the area of chip formation when cutting copper M1. According to the results of the research the value of shear deformation was calculated. The change of a rake angle tool γ leads to the change in the process of plastic deformation in the area of chip formation. It was found out that the maximum degree of shear deformation takes place in the contact area of tool tip and deformable sample.

Abstract: Most research on chip formation is based on free cutting with a single shear plane (the approach proposed by I.A. Time). No account is taken of the two-dimensional blade geometry nor of the three-dimensional character of the deformation source in the cut layer. It is assumed that the transformation of the cut layer into chip is confined to a very narrow zone adjacent to the shear plane. By contrast, constrained cutting is characterized by a conditional threedimensional shear surface, which is analogous to the shear plane.

Abstract: This work contributes to a better understanding of wear mechanisms of ultrafine cemented carbide cutting tools used in turning operation of superalloy and high strength steels at high cutting speeds. The main objective of this work is to verify the influence of grain size and the cobalt content of ultrafine cemented carbide tools on tool life and tool wear mechanism. The main conclusions are that grain size and the cobalt content of ultrafine cemented carbide tools strongly influence tool life and tool wear involve different mechanisms. The wear mechanisms of different grain size and the cobalt content of ultrafine cemented carbide tools observed on the rake face at these conditions were adhesion and notch, at the end of tool life, adhesion was the main wear mechanism at higher cutting speeds.

Abstract: 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.

Abstract: Tool life tests of continuous cutting superalloy GH2132 were carried out by WC/Co cemented carbide cutting inserts of different grain size and cobalt content, and flank surface wear morphology of the cutting inserts were observed by ZEISS continuous zoom stereo microscope and microphotograph system. The results show that grain size and cobalt content strongly influence the cutting tool life and tool wear, grain refinement and proper cobalt content are help to improve the tool life and the wear resistance of WC/Co cemented carbide. The wear mechanisms of different grain size and cobalt content of ultrafine cemented carbide tools were adhesion and notch, among them, adhesive was the main wear mechanism at higher cutting speeds.

Abstract: For investigating the effect of ultrasonic treatment on the cooling and lubricating action of cutting fluid, an ultrasonic treatment system of emulsion fluid was developed to be used in cutting experiments. And the comparison experiments were carried out with YT15 tool turning 45 steel, under the conditions of dry cutting, fluid and ultrasonic treatment fluid. The results show that as ultrasonic treatment one used cutting forces decrease about 10%-15% and 5%-10% to dry cutting and fluid; the cutting deformation coefficients reduce too; and the machined surfaces are enhanced. Therefore, the cooling and lubricating performances of the fluid are improved by ultrasonic treatment. As a result, the using quantity of emulsion fluid would reduce indirectly, and this help to energy saving and emission reducing.

Abstract: The introduction and application of common finite element method (FEM) about the modern metal cutting theory research was stated emphatically. Graded self-lubricating ceramic tool materials was briefly introduced, and problems existed about simulating the metal cutting process using FEM are pointed out and discussed in this study.

Abstract: This work studies the effect of heat treatment and cutting velocities on machining cutting forces in turning of a Cu-11.8%Al-0.55%Be shape memory alloys. The heat treatment was performed to obtain samples with austenite and martensite microstructures. Cutting force was investigated using a 3-component dynamometer in several revolutions and data were analyzed using statistic tools. It was found that the resultant forces were higher in quenched alloy due to the presence of Shape Memory Effect. Chip formation occurred in a shorter time in the sample without the Shape Memory Effect.

Abstract: This paper focuses on finite element modeling of orthogonal cutting process of AISI 1045 steel using Modified Johnson Cook (MJC) as constitutive material flow model under various machining parameters. Finite element solutions of cutting forces, effective stresses and temperature are obtained for a wide range of cutting speeds and feeds. The effect of feed and cutting speed on cutting forces, effective stresses and temperature has been studied over a wide range of values. Percentage variation of each is also studied to predict co-relation with the different machining parameters.

Abstract: Metal cutting indicates a specific category of processes in which unwanted material is removed from workpeice by single- or multi-point cutting tools for making products meeting prescribed specifications. Parameter optimization in metal cutting plays an important role in satisfying quality requirements of machined parts at low production cost or time. It requires optimal selection of cutting speed, feed rate, depth of cut, and the number of passes. A brief review of recent progress on the optimization of cutting parameters is introduced in the present work. Some new machining practices expending in recent years are involved including hard turning, dry cutting, high speed machining, machining of difficult-to-machine materials and composites. Modeling skills for creating optimization models and optimization techniques for solving optimal or near-optimal solutions are summarized and analyzed.