Internally cooled tools and cutting temperature in contamination-free machining

Abstract

Whilst machining heat is generated by the friction inherent into the sliding of the chip on the rake face of the insert, the temperature in the cutting zone of both the insert and the chip rises, facilitating adhesion and diffusion. These effects accelerate the insert wear, ultimately undermining the tool life. Therefore, a number of methods have been developed to control the heat generation. Most typically, metal working fluids are conveyed onto the rake face in the cutting zone, with negative implications on the contamination of the part. Many applications for instance in health care and optics are often hindered by this contamination. In this study, microfluidics structures internal to the insert were examined as a means of controlling the heat generation. Conventional and internally cooled tools were compared in dry turning of AA6082-T6 aluminium alloy in two 3 3 factorial experiments of different machining conditions. Statistical analyses supported the conclusion that the chip temperature depends only on the depth of cut but not on the feed rate or on the cutting speed. They also showed that the benefit of cooling the insert internally increases while increasing the depth of cut. Internally cooled tools can therefore be particularly advantageous in roughing operations.

Efficiency in contamination-free machining using microfluidic structures

“…More details regarding suitable transformations of the response to overcome observed departures of the assumed homoscedasticity of the errors in the case of linear models are presented by Faraway (cf pages 53-58 in [23]). The parameters in Equation 8and (9) have been estimated as in the previous cases using the nlme library ( Table 3) [ Table 3 Thus there was no reason for excluding the two experimental results from the analysis. Moreover, even doing so, the resulting fitted model did not lead to significantly different estimates of the parameters.…”

“…Previous research in the field of indirect cooling methods has shown that it is possible to reduce significantly the cutting temperature. In particular, Ferri et al [9] compared the chip temperature in dry turning of the aluminium alloy AA6082-T6 when using conventional and internally cooled tools. Their main finding was that the internally-cooled tools appeared increasingly effective in containing the chip temperature while increasing the depth of cut.…”

Smart Cutting Tools and Smart Machining: Development Approaches, and Their Implementation and Application Perspectives

“…This paper presents the design concept, development processes, application principles for the above smart tools, for high precision and micro machining in particular. The paper also explores and discusses the implementation and application perspectives of those smart tools against the smart machining requirements from a number of industrial applications, such as micromachining maintained with constant cutting force, extrahigh speed micro drilling, and contamination-free machining of medical device or explosive materials [12,13].…”

An Independent Internal Cooling System for Promoting Heat Dissipation during Dry Cutting with Numerical and Experimental Verification

“…Since the initial description of this type of cooling system in the 1970s, a variety of improvements have been proposed. Ferri designed an internally cooled cutting tool consisting of a modified cutting insert, cooling adapter accommodating micro-channel, and tool-holder with inlet and outlet ports [11]. Minton created a modified tool-holder with an internally cooled tool to enhance the heat transfer [12].…”