Search results for "Metal cutting"

Heat in Metal Cutting

2008

This chapter provides comprehensive knowledge regarding thermal effects during the cutting process with both uncoated and coated cutting tools. Main heat sources and flowing heat fluxes into the tool, chip and workpiece are characterized and quantified. The heat distribution models that allow the analytical prediction of heat partition between the tool and the chip are specified. They consider such thermal properties as specific heat, thermal conductivity and diffusivity, Peclet thermal number, and heat transmission ratio, all as functions of temperature. Finite element method and finite difference method simulations applied to the prediction of temperature fields are outlined for turning a…

Trends in Metal Cutting Theory and Practice

2017

This chapter provides the state-of-the-art manufacturing systems that utilize various machining technologies in different manufacturing sectors. It highlights the challenges of the 21st-century manufacturing environment and characterizes numerous driven factors in modern machining technologies. They include more-established technologies, such as High-Speed Machining/Cutting, High-Performance Machining/Cutting, High-Efficiency Machining or currently developed ones, such as resource- and energy-efficient (generally sustainable) and hybrid machining. Practical examples and charts that document their importance in modern manufacturing are provided. Finally, some important future trends are over…

On the Computational Error in 3D Simulation of Cutting

2009

Metal Cutting Operations and Terminology

2008

This chapter presents a general description of the machining processes and machining operations using various classification criteria. The classification of machining processes is based on the energy source used and the type of generating mechanisms, whereas the classification of machining operations utilizes characteristic motions describing their kinematics. Some examples of turning, milling, hole making, broaching and threading operations are provided. Kinematics of typical cutting operations and appropriate standardized cutting parameters are described. The geometry of cutting tools in the tool-in-hand and tool-in-use systems, including relevant tool angles, is characterized.

Cutting Tool Materials

2008

This chapter provides the state-of-the-art materials engineering sector that produces cutting tool materials for different manufacturing branches. It highlights the special demands on this special material group for modern machining technologies. Five groups of cutting tool materials are characterized in terms of their mechanical and thermo-physical properties: high-speed steels, sintered tungsten carbides, cermets, ceramics and superhard materials, all as conventional (uncoated) and coated grades. The most popular techniques of coating deposition on various substrates are described. Practical examples of cutting tool inserts made of various materials produced by leading world manufacturers…

Influence of machining conditions on friction in metal cutting process – A review

2019

This paper presents a range of variable machining factors which influence substantially friction directly or by the tool wear developed in the cutting zone. The group of direct factors include the workpiece and cutting tool materials coupled, the cutting/sliding velocity, cooling media supplied to the tool-chip contact zone, modification of the tool contact faces by micro-texturing. Special attention was paid to the tool wear evolution and its pronounced effect on changes of the contact conditions.

Tribology of Metal Cutting

2008

This chapter provides comprehensive knowledge regarding tribological behaviour of the cutting zone and characterizes specific features of the tool–chip contact that influence friction mechanisms in this area. Adhesion, plastic deformation of contacting asperities and ploughing action of the cutting edge are selected as three predominant mechanisms controlling sliding friction between the tool and the chip. The two-zone model of the tool–chip contact distinguishing seizure and sliding regions is characterized, along with experimental evidence based on photoelastic and material flow line techniques. Corresponding stress distributions for plane and restricted-contact cutting tools are provided…

The effect of wear on the tetragonal-to-monoclinic transformation and the residual stress distribution in zirconia-toughened alumina cutting tools

1998

Abstract Zirconia-toughened alumina cutting tools have been examined after machining an AISI 1040 steel. The Raman spectrum of zirconia and the fluorescence spectrum from alumina have been used to determine the extent of the tetragonal-to-monoclinic (t-m) transformation and the residual stresses in and around the worn-out crater, respectively. Although about 15% vol. m-zirconia is present even in a brand new cutting tool, it was shown that the crater region undergoes the t-m transformation up to 40% vol. In both cases, the transformed zone is concentrated near the surface. The residual stresses in alumina are slightly compressive in the new cutting tool and away from the crater region, but …

Some observations on metal cutting with reference to the mechanical characteristics of working materials

1972

The hypothesis of the minimum work of Merchant is applied to materials with different yield points in traction and in simple compression on the assumption that these materials yield in accordance with the paraboloid yield-criterion. The experimental data obtained from cutting tests like those described in this paper may apparently be in good agreement with theoretical results. But closer examination reveals that the values of the shear angle φ depend largely on the cutting speed and on the feed p. r. All relationship between φ and (λ — γ) (difference between the friction angle on the rake face and the rake angle) must therefore take in account the influence of the above variables.

Recognition of Chip Forms by Means of Dynamic Force Spectrum Analysis

1993

In this study the ability to identify chip forms occurrs in the turning of austenitic stainless steel using dynamic force spectrum analysis has been tested. For this purpose the frequency spectra obtained from various metal cutting tests were recorded along with the static cutting forces. A dual channel analysis, based on the Fast Fourier Transform (FFT), was adopted to help identify the continuous/discontinuous (favourable/unfavourable) chip forming boundary. The results showed an acceptable correlation between the types of the frequency spectra and the types of chip forms. Finally, an original classification of the spectra obtained during turning of AISI 304 (DIN 1.4301) stainless steel i…