Sheri Kurgin, Jean M. Dasch, Daniel L. Simon, Gary C. Barber and Qian Zou
The purpose of this paper is to compare the performance of single- and dual-channel minimum quantity lubrication (MQL) for reaming spool bores in an automotive transmission valve…
Abstract
Purpose
The purpose of this paper is to compare the performance of single- and dual-channel minimum quantity lubrication (MQL) for reaming spool bores in an automotive transmission valve body.
Design/methodology/approach
Machining experiments are conducted under various parameters for both single- and dual-channel MQL. Comparison metrics include part surface temperature, spindle power consumption and hole quality. Experimental data from traditional through-tool flood coolant are provided as a baseline for spindle power consumption and part quality.
Findings
The results show that with proper tooling and machining parameters, dual-channel MQL can perform equivalently or better than flood coolant. Single-channel MQL was not deemed suitable for this machining application.
Practical implications
The results of the study show that MQL can be successfully applied for precision reaming of aluminum and can provide guidance in developing an MQL system.
Originality/value
Few studies have been performed for reaming holes in general, and very few studies have been performed for reaming with MQL. Reaming is a critical operation used to create holes with precise quality. No study was found in the literature review that directly compared the performance of single- and dual-channel MQL delivery systems.
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Sheri Kurgin, Jean M. Dasch, Daniel L. Simon, Gary C. Barber and Qian Zou
The purpose of this paper is to evaluate the cooling ability of minimum quantity lubrication (MQL) cutting fluid.
Abstract
Purpose
The purpose of this paper is to evaluate the cooling ability of minimum quantity lubrication (MQL) cutting fluid.
Design/methodology/approach
An experimental system is devised to find the heat transfer coefficient of MQL under simulated reaming conditions. Cooling rate of the specimen is measured with an infrared camera. The effect of air pressure and oil volume on cooling rate is tested. Metal cutting tests are performed to evaluate the effect of heat transfer coefficient on workpiece temperature.
Findings
Convective heat transfer coefficient for MQL increases with increasing air pressure. Oil volume has an indeterminate effect on the heat transfer coefficient; however, it is a dominant factor for controlling temperature during reaming.
Practical implications
The results of the study can provide guidance to optimize the temperature controlling ability of MQL for production.
Originality/value
There is limited information available in literature regarding the heat transfer coefficient of metal working fluids, particularly for MQL. In particular, experiments designed to investigate the effect of air pressure and oil volume on the heat transfer coefficient of the mist have not been previously documented. This information may be used to improve the overall cooling ability of MQL mist, thus increasing its effectiveness at controlling tool wear and maintaining part quality. The other major contribution of this work is to separate the role of the cooling and lubrication for controlling temperature while reaming aluminum. Prior to this study, there has been relatively little research performed for the reaming metal cutting operation, and still less for reaming with MQL. The nature of how metal working fluids control temperature is not fully understood, and this work provides insight as to whether cooling or lubrication plays the dominant role for reaming.