The Effect of Turning Parameter and Fiber Pullout on Machinability of Unidirectional EGFRP under Cryogenic Condition

Abstract

The non-homogeneous and anisotropic nature of composites poses challenges during machining, requiring the use of specialized cutting tools. GFRP materials were selected for their excellent elasticity, corrosion resistance, and high strength, making them ideal for applications in the aerospace and automotive industries. In this work, the surface quality of UD-GFRP composite bars during CNC machining in diverse machining conditions (dry, wet, and cryogenic) was investigated while considering the fiber-pullout issue. The UD-EGFRP composite materials have been machined with a polycrystalline diamond tool. The Taguchi-L9 orthogonal-array technique is used to investigate and further analysis. Three independent-variables feed rate, rotational speed or cutting speed, and depth of cut have been taken into account for their optimal design to get better machinability of EGFRP. This study also investigates the delamination criterion in composites and establishes the correlation between its input parameters and output responses. The findings revealed that cryogenic machining led to a notable improvement of 25.21% in surface roughness compared to the other lubrication methods. Also, the reduction from 84 µm to 34 µm in fiber-pullout signifies that cryogenic cooling effectively mitigated the occurrence of fiber-pullout.