1.3 Boyutlu Baskı Teknolojileri Sempozyumu (3D-BTS), 05 - 07 Mayıs 2016, İstanbul
DEVELOPMENT OF NOVEL NANOCOMPOSITE MATERIALS FOR 3D PRINTING Ebubekir ÇANTIa, Mustafa AYDIN1a, Ferhat YILDIRIMb, a.
University of Dumlupinar, Faculty of Engineering, Department of Mechanical Engineering, 43100, Kütahya, Turkey b. University of Dumlupinar, Faculty of Simav Technology, Department of Manufacturing Engineering Corresponding author:
[email protected]
Özet Bu çalışmada, ikiz-vidalı ekstrüder ile üretilen polimer nano-kompozit malzemelerin karakterizasyonunun yapılması hedeflenmiştir. Üretilen malzemelerin mekanik özelliklerinin değerlendirmek amacıyla, bu malzemeler kullanılarak 3 boyutlu yazıcı ile test numuneleri hazırlanmıştır. Hazırlanan numuneler shore-D sertlik, çekme ve 3 nokta eğme deneyleri ile test edilmiştir. Bu testlerin ardından, malzemelerin gösterdikleri mekanik davranışların altında yatan sebepleri incelemek için SEM mikrograf ve EDS çalışmaları yapılmıştır. Sonuçlar, ABS matris malzeme içerisine nano-parçacık takviyesinin çekme testinde UTS değerlerini takviyesiz malzemeye göre en az 13% iyileştirdiğini göstermiştir. Anahtar kelimeler: Nano-parçacık takviye, eklemeli imalat, 3 Boyutlu yazım, FDM tekniği, SiO2, MWCNTs.
Abstract In this study, mechanical properties of polymer nanocomposite feedstock materials, produced by using a twin screw extruder, were characterized. Different testing methods, including shore-D hardness, tensile test and 3 point bending test, were applied on standard testing samples, which were 3D printed using these composite feedstock materials. Scanning electron microscope (SEM) and Energy-dispersive X-ray spectroscopy (EDS) characterizations were performed to evaluate intrinsic material structure of the printed samples. Results indicate that addition of nanoparticles into ABS matrix improves average Ultimate tensile strength (UTS) values more than 13% compared to non-reinforced samples which should be regarded as a significant improvement on tensile properties. Keywords: Nano-particle reinforcement, additive manufacturing, 3D printing, FDM technique, SiO2, MWCNTs.
1. Introduction Decreasing cost of 3D printers has increased its accessibility and expanded its applications from research laboratories to industries in the last decade. As a result of this, wide-spread implementation of additive manufacturing (AM) in various fields including medicine and biotechnology, as well as daily home use is expected with explosive future prospect [1]. Additive manufacturing relies on principle which is joining of the materials by different techniques to make objects directly from 3D model data of them. In this point of view, AM differs from conventional manufacturing techniques, which require forming, molding, and cutting instruments, while reducing manufacturing time and cost [2]. Such advantages render AM as an extraordinary manufacturing process. Fused Deposition Modeling (FDM) is one of the most prominent AM techniques with potential implementation fields in today and near future. Compared to other AM techniques, low cost of the printing devices and broader availability of the stock materials makes FDM technique unique [3]. In FDM process, polymeric materials are generally used as the building material. The process involves extrusion of the melted polymer
through the nozzle on a building platform. Even though this approach has some similarities with conventional extrusion process, due to the mobility of the nozzle component in X, Y and Z axes in FDM process make conventional mold using redundant in thermoplastic forming. While this unique property reduces production costs, it also allows customized designs and differs from conventional extrusion processes with standardized design due to the large quantities in this aspect. There has been significant amount of research effort directed at FDM technique because it allows to manufacturing complex shaped parts and reduce prototyping costs [4]. Properties of the produced parts via FDM are affected many parameters. The efforts have been mainly directed to understanding the influence of manufacturing parameters, including the air gap between adjacent beads, raster orientation and bead with in FDM process. However, material selection stays as a significant parameter [5] which determines resultant properties of the parts to be manufactured. In FDM process, Acrylonitrile butadiene styrene (ABS), polycarbonate, and Polylactic acid (PLA) are frequently used as feedstock materials. Nonetheless, inadequate mechanical properties of these materials restrict production of fully functional parts via FDM [6]. Developing advanced materials can address challenges in production of functional components, arising from intrinsic properties of polymeric materials, in FDM based 3D printing. Mechanical properties of polymeric materials produced through addition of other materials as fillers have been investigated in the literature. It has been shown that addition of very low content of nanoparticles into polymer matrix, which is known as nanocomposites, can provide improved mechanical properties [7]. Due to this unique advantage, the nanocomposites polymers hold a great potential to be utilized as a filaments for FDM based 3D printing. In this study, mechanical properties of polymer nanocomposite feedstock materials, produced by using a twin screw extruder, were characterized. Different testing methods, including shore-D hardness, tensile test and 3 point bending test, were applied on standard testing samples, which were 3D printed using these composite feedstock materials. SEM and EDS characterizations were performed to evaluate intrinsic material structure of the printed samples.
2. Experimental Studies 2.1. Materials In this study, SiO2and MWCNTs powders were used as reinforcement for the production of ABS nanocomposite feedstocks. The SiO2 and MWCNTs powders were purchased from Ege Nanotech (Izmir, Turkiye, code EN/N-EA234 and EN/N-KNT14-1, respectively). ABS pellets supplied by Bhansali Engineering Polymers LTD (India) with IM-21 AS code.The powders have different properties, including density, surface area, purity and particle morphology. Material properties of the used nano particles were presented in Table 1. Table 1. Properties of the reinforcement materials. Properties
Unit
Density Surface Area Purity Morphology Outer Diameter Inner Diameter Length
gr/cm3 m2/gr % nm nm µm
Reinforcements MWCNTs SiO2 2,1 2,2-2,6 40 440 >95 99,90 Tube Spherical < 50 30
