Influence of milling process parameters and significance of tools to improve the surface quality of GFRP composites

Abstract

The anisotropic nature of polymer composites presents many challenges for manufacturers to adopt appropriate machining processes. In the present investigation, end milling experiments were conducted on glass fiber reinforced polymer laminates with five varieties of customized cutting tools with different angles of rake and clearance. The performance of the tools was evaluated in terms of their machining force, surface roughness and delamination factor at spindle speeds in the range of 690–2500 rpm. From the observations, relatively high rake and angled clearance tools performed better than the rest of the tools under consideration in terms of delamination and machined surface finishing. The milling operations performed at a spindle speed of 1950 rpm produced better surface quality. Observations from SEM graphs, exposed surface defects due to milling, generated at lower spindle speeds of 690 rpm and at higher spindle speeds of 2500 rpm with the tool signature of low angle rake and angled clearance tools out of all five tools considered for the experiments.

KEYWORDS:

• Bi-directional glass fiber reinforced polymers
• conventional milling
• customized carbide tipped tools
• surface integrity
• SEM