Effects of tool material, tool topography and minimal quantity lubrication (MQL) on machining performance of compacted graphite iron (CGI)

Abstract

This paper addresses the tribological challenges involved in the machining of compacted graphite iron (CGI) through an investigation of the effects of tool material, local tool surface topography and minimal quantity lubrication (MQL) on machining performance. Turning experiments were undertaken using four different tools (flat coated carbide, grooved coated carbide, grooved coated cermet and chamfered ceramic) under dry and MQL conditions. The tests were conducted at two different cutting speed conditions with a constant feed and depth of cut. Results reveal that at low speed, the cermet tool provides a significant reduction in cutting forces in comparison to coated carbide. Cutting forces show an increase with the usage of MQL at high speed, suggesting a negative influence of the cutting fluid on CGI machining performance. Scanning electron microscopy/energy dispersive X-ray analysis of the tested tools reveal the absence of MnS layer on tools used for CGI machining, thereby reconfirming the findings by other researchers.

Keywords:

• COMPACTED GRAPHITE IRON
• MINIMAL QUANTITY LUBRICATION
• CUTTING FLUID
• DRY MACHINING
• CERMET
• CUTTING FORCES