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In this article, Deform© three-dimensional package was used to develop a numerical model for friction stir process of Polyamide 6 based on Lagrangian incremental formulation, and additional experiments were done to verify this objective. For this purpose, the friction stir process was used to disperse the multi-walled carbon nano-tubes among the polymer matrix of Polyamide 6 homogeneously. Thermo-mechanical properties, for example, effective plastic strain distribution and material flow together with temperature, were successfully predicted for friction stir processing of Polyamide 6. X-ray diffraction and scanning electron microscopy were used to study the properties of fabricated nano-composite. According to the results, multi-walled carbon nano-tubes were homogeneously and straightly dispersed throughout Polyamide 6. The straight and non-curved dispersion of multi-walled carbon nano-tubes results in the growth of their reinforcement capability. Comparing the result of simulation and experimental friction stir process refers to good agreement between simulation predictions and actual observations. Temperature distribution study shows that the peak temperature appears at the interface of tool-shoulder/work-piece and the temperature distribution on the interacted surface is asymmetric. On the other hand, the analysis of effective plastic strain indicates that the material shearing of advancing side is higher than that of the retreating zone.

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Nowadays, polymer nano-composites have attracted manufacturers’ attention because of good mechanical, thermal, and physical properties. During the past decade, the requirement of the direct machining of polymer nano-composites increases because most of the polymer nano-composites were produced by extrusion method in simple cross section shapes and request for personalized products increases. In this study, the effect of milling parameters (spindle speed and feed per tooth) and nano-CaCO3 content on the machinability properties of PA-6/nano-CaCO3 composites was studied by means of analysis of variance. Additionally, the effect of nano-CaCO3 content on the mechanical properties of PA-6/nano-CaCO3 composites was investigated. To this end, several experiments were carried out on PA-6/nano-CaCO3 composites to attain the required data. The results reveal that the nano-CaCO3 content on PA-6 significantly decreases the cutting forces, but does not have a considerable significance on surface roughness.

Growing global environmental threats have attracted researchers and engineers toward design and manufacture of green materials. In this regard, natural filler reinforced composites are environmentally friendly, cost-effective materials with a lot of advantages over conventional carbon/glass fiber reinforced composites. Hence, in this study, the drilling performance of walnut shell powder reinforced composite material was experimentally investigated. For this purpose, the composite specimens were first fabricated by injection molding process, followed by further drilling tests, which were performed with and without ultrasonic vibration. The effect of drilling parameters and ultrasonic vibration was investigated on surface roughness, thrust force and geometrical tolerances (circularity and cylindricity), as the process performance parameters. The obtained results demonstrated that by increase of the spindle rotational speed and decrease of feed rate, the thrust force, surface roughness and geometrical tolerances were reduced. Also, it was seen that ultrasonic vibration could effectively enhance the performance parameters, which was attributed to the intermittent cutting process and impact action of ultrasonic vibration, leading to reduced friction, improved material removal, reduced cutting forces, and better surface quality.