Machinability Performance Investigation of TiAlN-, DLC-, and CNT-Coated Tools during Turning of Difficult-to-Cut Materials

Abstract

Titanium alloy-based components are now attracted by the industries with their distinguished properties even though they are difficult to machine. The tooling industries encounter numerous problems in machining these metals like higher tool wear, huge volumes of cutting fluid consumption, and shorter tool life. The objective of this research is to enhance the surface of the cutting tool with carbon nanotube (CNT) deposition to solve the aforementioned difficulties. This research used the plasma-enhanced chemical vapor deposition method to coat CNT on high-speed steel tools. Microstructural investigations were performed using a scanning electron microscope and a Raman spectroscopic technique to ensure the homogenous deposition of CNT. Additionally, scratch testing was also conducted to assess the adhesive strength of the deposited layer to the substrate. Finally, the machining performance of the CNT-coated tool was compared with commercially available diamond-like carbon (DLC) and titanium aluminum nitride (TiAlN)-coated tools. Machining experiments conducted under three distinct cutting levels revealed that the CNT-deposited tool is appropriate for turning more challenging materials. CNT-coated tools showed substantial decreases in cutting tooltip temperature, turning forces, and tool wear compared to DLC and TiAlN-coated tools. In particular, tool life studies conducted under elevated machining circumstances recorded the enhancement in tool life as 96.3% and 26.8% in comparison with TiAlN and DLC, respectively.