Papers by Keyword: Cutting Edge Radius

Abstract: In terms of machinability are titanium alloys classified in the group of difficult to cut materials. The main factors determining this status are limited tool life, high generated cutting forces (torque) and temperature in cutting zone caused by low thermal conductivity as well as chemical reactivity with cutting tool. Solid carbide drills still remain as preferred choice in hole making process when machining Ti6Al4V alloy. Besides cutting conditions, tool and cutting edge geometry significantly affect the value of torque. Reduction of process energy requirements can be achieved by appropriate optimization of these parameters. Mathematical model describing influence of cutting speed, feed rate, clearance angle and cutting edge radius on investigated variable with high reliability coefficient (R²=96.72%) was found. Drilling experiments were designed and carried out using Taguchi orthogonal array L₁₆.

Abstract: Inconel 718 alloy is a typical difficult-to-cut material and widely used in the aerospace industry. Finite element simulation is an efficient method to investigate the cutting process, whereby a work material constitutive model plays an important role. In this paper, finite element simulation of the cutting process for Inconel 718 alloy using a new material constitutive model for high strain rates is presented. The effect of tool cutting edge radius on the cutting forces and temperature is then investigated with a view to facilitate cutting tool design. It is found that as the cutting edge radius increases, the characteristics of tool-work friction and the material removal mechanisms change, resulting in variation in cutting forces and temperature. It is shown that a smaller cutting edge radius is preferred to reduce the cutting forces and cutting temperature.

Abstract: Chip formation is a dynamic process that is often nonlinear in nature. A chip may not form when the depth of cut is less than a minimum chip thickness. It is aimed to investigate influence of depth of cut on contact phenomenon in micromachining. This paper presents a series of simulation works by finite element method on depth of cut effect on micromachining. A model is developed with consideration of the Johnson-Cook material and Arbitrary Lagrangian–Eulerian (ALE) method. In this work investigate the effect of depth of cut on the contact phenomenon during micromachining AISI D2. The results of the analysis are showed in aspects of interrelationship between material separation and frictional shear contact, distribution of stick-slide regions and contact stress on the work piece and cutting tool. It is found that the sticking and sliding was occurred on three zones as primary, secondary and tertiary shear zone. The contact phenomena can be showed around the tool edge radius where material flows around it and piles in front of the cutting tool through material separation. The investigation of contact phenomena inclusive under three criteria such as a/r < 1, a/r > 1 and a/r = 1 on positive rake angle.

Abstract: Chip formation is a dynamic process that is often non linear in nature. A chip may not form when the depth of cut is less than a minimum chip thickness. This paper presents an investigation of cutting edge radius effect on micromachining AISI D2 tool steel via simulation. The chip growth, chip formation and material deformation mechanism was investigated using commercial finite element analysis software. A model is developed with consideration of the arbitrary LagrangianEulerian (ALE) method. The chip growth, chip formation and material deformation was investigate under three criteria such as a/r<1, a/r>1 and a/r=1. The model showed that the chip is formed at a/r >1 while material extrusion performed under a/r<1.

Abstract: Micro machining becomes more and more important with the tendency of miniaturization of components used in various fields from military to civilian applications. The finite element method software Abaqus is used to model the nonlinear thermal force coupled elastic-plastic micro machining processes. Relatively systematic simulation analysis has been introduced based on the model combining the Johnson-Cook failure criteria, element deletion strategy etc. It reveals that the size effect is dominant while the depth of cut reaches the cutting edge radius. The rake angle plays more important roles on the micro machining than that of the cutting speed.

Abstract: Surface roughness plays a critical role in evaluating and measuring the surface quality of a machined product. Two workpiece materials have been investigated by experimental approach in order to gain a better understanding of their influence on the obtained surface roughness in the micro-milling processes. The experimental results show that: surface topography is completely different for different materials at the same cutting speed and feed rate; surface roughness increases with an increase of material grain size. Surface roughness decreases to a lowest value, and then increases with an increase of the feed rate. A new surface model to illustrate the influence of material and uncut chip thickness was developed. The model has been experimentally validated and shows more promising results than Weule’s model.

Abstract: Regrinding of wasted cutting tools can recycle resources and decrease manufacturing costs. Influence of relative tool sharpness and tool cutting edge angle on tool edge radius were analyzed. Cutting force and cutting temperature were simulated with FEM on different edge radius. Edge preparation experiments were carried out though an abrasive nylon brushing method. The results show that RTS and cutting edge angle have influence on edge radius. Small edge radius might result in small cutting forces and lower average temperatures, could maintain the cutting state between tool and workpiece. The cutting edge defects can be eliminated through edge preparation, and a smooth cutting edge can be obtained. Cutting tool life will be improved through proper edge design and edge preparation.

Abstract: In order to obtain the influences of cutting edge radius on cutting deformation in high-speed machining Ti6Al4V, cutting temperature, equivalent stress distribution, the chip morphology and cutting deformation coefficient were analyzed in this paper. The results indicated that cutting edge changed the plastic flow of materials around tool tip and the actual tool rake angle, the tool-workpiece and tool-chip contact in cutting process which causes a greater impact on physical and mechanical performance in the given cutting conditions. When the cutting edge radius reached to 0.04mm,the cutting temperature and the equivalent stress existed mutations, which causes the mutation of chips. There was a chip thinning effect with the increase of the cutting edge radius. As the cutting edge radius increased, chip thickness and shear angle decreased, cutting deformation coefficient increased.

Abstract: In micro-cutting process, a remarkable characteristic of micro-Cutting is that cutting parameters level closing to the crystal grain msize of material. Though, the prediction formula of micro-cutting forces should reference to strain gradient plasticity theory in formula construction , while cutting edge radius had been regard as a important parameters in the process of micro-cutting. With advantedge FEM software for simulation of micro-cutting , the results show that, there was no significant effect of temperature on cutting force; strain gradient reaction will be decreased by feed rate’s reducing in process, cutting depth effected cutting force in linear mode, the max. workpiece temperature area is no longer the second deformation area but the primary deformation zone, while the max. temperature area of the tool would transfer to the tool tip from theoretical location of traditional cutting.

Abstract: On the basis of analyzing the cutting edge structure and cutting edge radius measurement of high-speed insert, thermal - mechanical coupling finite element method (FEM) is used in this paper, to obtain the effect law of different cutting edge radius on the mechanical-thermal distribution of high-speed cutting TiAl6V4. At last, cutting experiments are carried out to verify FEM results. There is a clear exposition of the intrinsic reason why the cutting edge radius has influence on the mechanical -thermal distribution of high-speed cutting process. The results indicate that the experimental results have a good agreement with FEM; with the cutting edge radius increases, cutting force increases; cutting temperature is not monotonic, but there exists an optimum edge radius that makes temperature lowest; cutting edge changes the plastic flow of materials around tool tip and broaden plastic deformation zone. The cutting edge radius has a greater impact on equivalent stress.