Chung-Shin Chang

Prediction of the cutting forces for chamfered main cutting edge tools

A new cutting model of various tool geometries for tools with a chamfered main cutting edge has been built. Theoretical values of cutting forces were calculated and compared with the experimental results; the forces predicted by this model were consistent with the experimental values. Special tool holders were designed and manufactured to obtain various tool geometries. Cutting experiments were conducted on a carbon steel to examine the mechanism of secondary chip formation; the relationship between the shapes of secondary chips and tool geometries was observed.

A force model for nose radius worn tools with a chamfered main cutting edge

The three-dimensional cutting forces for nose radius tools with a chamfered main cutting edge incorporated with a tool-worn factor are presented in this paper. The variations in shear plane areas occurring in the tool-worn situation are used. The results obtained from the proposed model shows good agreement with the experimental data on both chip formation as well as cutting forces. In the experimental work the throwaway tips are locked onto the pocket of the tool holder. The holders for special tools are designed first. Next, the tool holders are manufactured by using medium carbon-steel bars and the mounting tips are designed based on various specifications. Finally, the nose radius tips mounting in the tool holder are ground to a wear depth, and the worn tool dimensions are measured by using a profile projector. The shear area and the friction area are calculated accordingly. Then the three-dimensional cutting forces will be obtained from those data.

Turning of stainless steel with worn tools having chamfered main cutting edges

A force model is proposed in this study for a single-point tool with a chamfered main cutting edge incorporating a wear factor. The variations of shear plane areas occurring in the tool-worn situation are also used. Cutting experiments are conducted on stainless steel bars and the experimental data correlated closely with the theoretical values. A preliminary discussion is also made of the design of special tool holders and their geometrical configurations. The tool holders were milled using medium carbon-steel bars and these holders with the mounting tips were ground to fit various specifications.

A force model of turning stainless steel with worn tools having nose radius

Abstract To study cutting forces, tip’s surface temperature, the mechanism of secondary chip and main chip formation when turning stainless steel with a chamfered main cutting nose radius tool are considered to have pre-wear. A holder with special tools and geometry are designed first. Secondly, the tool holders made of medium carbon steel bars are milled and ground to make them fit to various specifications. Finally, the tip’s mounting in the tool holder are ground to wearing depth measured with a toolmaker’s microscope and a new force model incorporating a tool pre-wear factor using the variations of shear plane areas cooperating with tool pre-wear situations is made. After the cutting processes have occurred, more wear factors of tool are considered in the force model. For successfully predicting cutting forces, however, shear plane areas vary due to the wearing effects of the tool edge in cutting stainless steel.

An experimental study of the chip flow of chamfered main cutting edge tools

Special tool holders and their geometrical configurations were designed for the purpose of improving the cutting efficiency of turning tools and extending tool life. The proposed tool holders were milled using medium-carbon steel bars and ground with mounting tips to various specifications, to provide chamfered main cutting edge tools with a secondary chip. To examine the mechanism of secondary chip formation in this research, cutting experiments were conducted on pure aluminum and carbon steel. Also, the ideal tool geometry, the relationship between the shape of the main and secondary chip and the wear of tip on the main cutting edge were investigated.

A study of high efficiency face milling tools

Abstract A new predictive force model for a single-tooth face milling cutter with a chamfered main cutting edge has been derived. Machining tests has been conducted for fly cutting with a chamfered main cutting edge tools on plane surfaces. An S45C medium carbon plate has been used as the workpiece matrial. Force data from these tests were used to estimate the empirical constants of the mechanical model and to verify its prediction capabilities. The results show a good agreement between the predicted and measured forces. Since tool manufacturers does not provide tools with selected combinations of chamfered main cutting edge, radial angle, axial angle and inclination angles, tool holders manufactured in-house were used in the tests. The tips were prepared to the required geometry using a tool grinder.

A force model for a single-point tools with a chamfered main cutting edge

Abstract A force model for a single-point tool with a chamfered main cutting edge was proposed in the present study. The experimental data were confirmed by the turning experimental results to be in close correlation with the theoretical values. Initially, special tool holders and their geometrical configurations were designed and discussed. The proposed tool holders were milled using medium-carbon steel bars and grinded with the mounting tips to various specifications. Cutting experiments were conducted on pure aluminum and carbon steel for studying the mechanism of the formation of a secondary chip; and in addition, the ideal tool geometrical configurations of the relationship between the shapes of the secondary chip and the tool geometries were observed.

A Study of Cutting Performance in Turning Plain Carbon Steel Using TiN-Coated, TiCN-Coated, and Uncoated Cemented Carbide Tools with Chamfered Main Cutting Edge

Abstract A special tool holder and its geometry was designed for this study. The tool holders, made of medium carbon steel, were milled and ground to various specifications. Tools of three kinds, i.e., TiN-coated, TiCN-coated and uncoated with chamfered main cutting edge (CMCE) were used in turning of carbon steel and pure aluminum to study the mechanism of secondary chip formation. According to the overall performance, the coated CMCE tools were better than the uncoated CMCE tools. In regard to the values of cutting forces and current consumption, the surface roughness of the work piece and the temperature of the tip surface, the levels of coated CMCE tools were all smaller than for the uncoated ones. The cutting force for the TiCN-coated CMCE tools was smaller than that of the TiN-coated ones. From the surface roughness of the work piece, the TiN-coated CMCE tools showed better results. From the color of the main chip and the hardness of the secondary chip, the temperature of the secondary chip was dete...

Turning of Stainless Steel with Chamfered Main Cutting Edge Tools

Abstract A force model for a single-point tool with the chamfered main cutting edge was proposed in this present study which could consequently result in tools being manufactured which produce a built-up edge (BUE). Special tool holders and their geometrical configuration were designed and are discussed in the initial stages of this paper. The tool holders were milled using medium-carbon steel bars and these holders with the mounting tips were ground to fit various specifications. The experimental results correlated closely with the theoretical values predicted by the model. Cutting experiments were conducted on stainless steel and carbon steel for studying the mechanism of the secondary chip; in addition, the ideal tool geometrical configurations of the relationship between the shapes of the secondary chip and tool geometries were observed.

A force model of a single-point tool with a chamfered main cutting edge when wearing has occurred

Abstract A force model was proposed in this study for a single-point tool with a chamfered main cutting edge incorporating a worn-tool factor. The variations of shear plane areas occurring in the worn-tool situation were also used. Experimental data correlated closely with the theoretical values. A preliminary discussion was also made of the design of special tool holders and their geometrical configurations. The proposed tool holders were milled using medium-carbon-steel bars and grinded tool wear with the mounting tips designed according to various specifications.