Fiber orientations effect on process performance for wire cut electrical discharge machining (WEDM) of 2D C/SiC composite

Abstract

Adopting orthogonal experiments, relevant machinability in wire cut electrical discharge machining (WEDM) of 2D C/SiC composite was studied. The effects of electrical machining parameters (namely pulse width, pulse interval, and the number of tubes) on machining speed and surface roughness were analyzed. In addition, the effect of fiber orientations on the machinability was also studied. The main effect and interaction of the selected electrical machining parameters were also discussed. The key results show that the fiber orientation effect on machining speed plays a weaker role in WEDM of this composite. For machining speed, the number of tubes and the pulse interval have no interaction in both of machining directions A and B. For surface roughness, the number of tubes and the pulse interval have obvious interaction in both of machining directions A and B. The fiber orientation has a larger effect on the surface roughness than that on machining speed in WEDM of this composite. After analyzing the material removal mechanism, some new significant results show that the carbon fibers are removed in the form of transverse and longitudinal fracture. Interfacial debonding between fiber carbon and SiC matrix, pit, and recast layer form on the machined surface. Micro cracks are observed in the carbon fiber, and a part of the micro cracks are cross.