Cutting temperature measurement during titanium machining with an atomization-based cutting fluid (ACF) spray system

The poor thermal conductivity and low elongation-to-break ratio of titanium lead to the development of extreme temperatures localized in the tool-chip interface during machining of its alloys and cause accelerated tool wear. The atomization-based cutting fluid (ACF) spray system has recently been demonstrated to improve tool life in titanium machining. In order to understand the cooling and lubrication mechanism of the ACF spray system, it is important to determine the temperature gradient developed inside the entire tool-chip interface. The objective of this work is to measure the cutting temperatures at various locations inside the tool-chip interface during titanium machining with the ACF spray system. The temperature gradient and mean cutting temperature are measured using the inserted and the tool-work thermocouple techniques, respectively. Cutting temperatures for dry machining and machining with flood cooling are also characterized for comparison with the ACF spray system temperature data. Findings reveal that the ACF spray system more effectively reduces cutting temperatures over flood cooling. The tool-chip friction coefficient data indicate that the fluid film created by the ACF spray system also actively penetrates the tool-chip interface to enhance lubrication during titanium machining, especially as the tool wears.