Investigation of titanium dry machining using chilled air

Titanium has traditionally been machined using liquid flood coolant, but dry machining can be used in situations where liquid coolant unable to be used. The work piece can be cooled by a focused stream of air alone. The properties of the air used can be altered by the use of a vortex tube to cool the air, but in cooling the air, the vortex tube reduces the volumetric air output. These experiments were set up to determine what settings of the air cooling and what machining parameters would result in the best tool life when milling titanium with a 1/2 inch diameter, 4-flute, coated carbide bit. The experiments also required investigating how the coated carbide tools change as they wear, and how to measure the changes. The bits were inspected under optical magnification to find chips and measure the coating wear, and the surface roughness of the machined surfaces was measured. The experimental data was then analyzed using ANOVA analysis to determine what factors contribute to the tool wear --Abstract, page iii