Microstructure and mechanical properties of PA۶/NBR nanocomposites fabricated by friction stir processing

Thermoplastic elastomer (TPE) based on polyamid۶ (PA۶) / acrylonitrile-butadiene rubber (NBR) containing ۵% wt nanoclay (Closite ۳۰B) have been prepared via friction stir process (FSP). In this study, the essential work of fracture (EWF) approach was employed to investigate the fracture behavior of PA۶/NBR nanocomposites. Also, the modulus strength of specimens was modeled by response surface methodology (RSM), considering three input variables including rotational speed (ω), traverse speed (S), and shoulder temperature (T). Thus, a quadratic mathematical model between input variables (ω, S and T) and response (modulus strength) of PA۶/NBR/clay nanocomposites was achieved. Moreover, the morphology of the PA۶/NBR blends containing ۵% wt was investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results show that a sample of PA۶/NBR thermoplastic elastomer (TPE) containing ۵% wt nanoclay at maximum tensile strength exhibited the maximum specific essential work of fracture (we) and specific non-essential work of fracture (wp). Also, the results of the RSM method demonstrate that the optimum condition of the process was found to be at including rotational speed (ω), traverse speed (S), and shoulder temperature (T) of ۱۲۰۰ rpm, ۲۵mm/min, and ۱۴۶ ℃, respectively. Thus, under the condition optimum, maximum modulus strength of ۶۵۸ MPa was obtained.