Surface integrity in material removal processes: Recent advances

Machining difficult-to-machine materials such as alloys used in aerospace, nuclear and medical industries are usually accompanied with low productivity, poor surface quality and short tool life. Despite the broad use of the term difficult-to-machine or hard-to-cut materials, the area of these types of materials and their properties are not clear yet. On the other hand, using cutting fluids is a common technique for improving machinability and has been acknowledged since early 20th. However, the environmental and health hazards associated with the use of conventional cutting fluids together with developing governmental regulations have resulted in increasing machining costs. The aim of this paper is to review and identify the materials known as difficult-to-machine and their properties. In addition, different cutting fluids are reviewed and major health and environmental concerns about their usage in material cutting industries are defined. Finally, advances in reducing and/or eliminating the use of conventional cutting fluids are reviewed and discussed.

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Environmentally conscious machining of difficult-to-machine materials with regard to cutting fluids

On The Measurement of Temperature in Material Removal Processes

Coated tools constitute the majority of the tools applied in material removal processes, rendering the employment of uncoated ones as an exception. A broad growing market of coated cutting tools has been developed. Moreover, numerous material- and manufacturing-engineers have joint their expertise, aiming at developing coatings meeting the needs for processing the most difficult-to-cut materials at the most extreme cutting conditions. The emerging of new workpiece, tool and film materials, the evolution of sophisticated coatings’ characterization methods and the continuous need for higher productivity rates, maintain vivid the industrial and scientific interest for further advancing this field.

Cutting with coated tools: Coating technologies, characterization methods and performance optimization

Capability Profile of Hard Cutting and Grinding Processes

Highly stressed steel components, e.g., gears and bearing parts, are appropriate applications for hard turning. Therefore, the process effects on significant engineering properties of work materials have to be carefully analyzed. Roughness, residual stresses, and white layers as parts of surface integrity, are functions of the machining parameters and of the cuttability of the cutting edge, i.e. of the tool wear. The aim of this work was to study the influence of feed rate, cutting speed, and tool wear on the effects induced by hard turning on case-hardened 27MnCr5 gear conebrakes and to point out the technical limitations in mass production.

Surface integrity in finish hard turning of case-hardened steels

Thermal influence of cutting tool coatings

The paper deals with the qualification of the thermal behaviour of the system work material - coated carbide cutting tool - chip, with the purpose of reaching a better understanding of the heat flow entering into the tool substrate during a turning operation. Heat transfer in deposit-substrate system was analysed by basing on a simple geometry example. A model of heat transfer in the cutting tool has been proposed. Results show that coating's thermal barrier role does not exist in continuous cutting operations, but that it is significant in discontinuous cutting operations especially with high speed cutting conditions.

A. Moisan

Papers

Surface integrity in finish hard turning of case-hardened steels

Thermal influence of cutting tool coatings

Thermal influence of cutting tool coatings