TECHNICAL PAPER Melt processing for enhancing compatibility of aluminum-reinforced acrylonitrile–butadiene–styrene and polyamide 6 for friction welding applications Ranvijay Kumar 1,2 • Rupinder Singh 1 • I. P. S. Ahuja 2 Received: 30 September 2017 / Accepted: 9 July 2018 Ó The Brazilian Society of Mechanical Sciences and Engineering 2018 Abstract Friction welding is one of the established solid-state welding techniques with wide aerospace, automobile and industrial applications. For thermoplastic components, it is extremely difficult to join the dissimilar material [e.g., acrylonitrile butadiene styrene (ABS) to polyamide (PA) 6] with friction welding process. For such joining/welding applications, there is a need of strong material compatibility/processing technique. This study highlights melt flow index (MFI) as one of the rheological/flow properties which can be used as controlling parameter for dissimilar thermoplastic friction welding. The twin screw extrusion and fused deposition modeling as melt processing techniques have been used for processing/fabri- cation of functional/non-functional surfaces/prototypes. The results of study suggest that ABS with 15% Al metal powder by weight (ABS-15Al) and PA6 with 50% Al metal powder by weight (PA6-50Al) have a similar range of MFI as 11.57 and 11.97 g/10 min, respectively (which confirmed the compatibility for joining of both polymers by friction welding). The results are supported by photo-micrographs and mechanical testing. Keywords Polymer compatibility Á ABS Á PA6 Á Twin screw extrusion Á FDM Á Friction welding Á Porosity 1 Introduction The dissimilar thermoplastics are having different mechanical, thermal, rheological, chemical and morpho- logical properties, which hinders solid-state welding applications [1–5]. The issue of non-compatibility occurs because thermoplastics are categorized by their unique carbon chain length, flow ability, morphology, molecular weight, molecular density, thermal behavior and chemical behavior. Polymeric composites are most commonly prepared by extrusion or molding (e.g., injection molding, single-screw extrusion, multi-screw extrusion and casting processes) for its applicability in the engineering field like automobile, structural, maintenance. Some studies have outlined that single-screw extrusion and double-screw extrusion are most widely used techniques for polymer composite preparations. The TSE has emerged as the advance technique which provides the better mixing, morphology and mechanical characteristics over conven- tional extrusion process for composite preparations [6]. Different destructive and non-destructive techniques like X-ray diffraction (XRD), tensile properties, micro-hard- ness, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) are used for ascertaining mechanical properties of thermo- plastics [7]. Injection molding concept is widely used for the development of multi-functioning component with provision of either no loss or improvement of material characteristics. Some of the recent studies highlighted the cross-linking of PA6 polymer chain with use of diamond nanoparticles in PA6 matrix and potential of PA6 for various industrial applications, while using the TSE for Technical Editor: Ma ´rcio Bacci da Silva. & Rupinder Singh rupindersingh78@yahoo.com Ranvijay Kumar ranvijayk12@gmail.com I. P. S. Ahuja ahujaips@gmail.com 1 Department of Production Engineering, Guru Nanak Dev Engineering College, Ludhiana, India 2 Department of Mechanical Engineering, Punjabi University, Patiala, India 123 Journal of the Brazilian Society of Mechanical Sciences and Engineering (2018)40:378 https://doi.org/10.1007/s40430-018-1298-y