Experimental and modeling investigation of surface roughness in end-milling of polyamide 6/multi-walled carbon nano-tube composite

Abstract

Nowadays, Manufacturers tend to use polymer nano-composites as raw material because of their high thermo-mechanical properties and strength to weight ratio. Due to production methods of nano-composites which result in simple cross-sections and rising demands for private products, the need for machining polymers has increased. In this study, the surface roughness of polyamide 6/multi-walled carbon nano-tube composite has been investigated after end-milling. The nano-composite samples were produced with 3.5 wt% of multi-walled carbon nano-tube by friction stir process. In order to ensure the quality of fabricated nano-composites, X-ray diffraction and scanning electron microscopy were used to evaluate it. End-milling was conducted at different levels of spindle speed and feed per tooth on polyamide 6 (with and without multi-walled carbon nano-tube) to study the resulted surface roughness. Then, analysis of variance was conducted to evaluate the parameters’ influence on surface roughness. Additionally, the optimal cutting parameters were determined by coupling artificial neural network and harmony search algorithm. Results reveal that surface quality increases with decrease of feed per tooth, and increase of spindle speed and carbon nano-tubes improve the surface quality.