Chifor et al. / J Zhejiang Univ-Sci A (Appl Phys & Eng) 2011 12(8):583-592 583 An experimental investigation of properties of polyethylene reinforced with Al powders Victoria CHIFOR 1 , Zafer TEKINER ‡2 , Mehmet TURKER 2 , Radu ORBAN 1 ( 1 Department of Materials Science and Technology, Faculty of Materials Science and Engineering, Technical University of Cluj-Napoca, Cluj-Napoca 400641, Romania) ( 2 Mechanical/Metallurgy Education Department, Faculty of Technical Education, Gazi University, Ankara 06500, Turkey) E-mail: chifor_victoria@yahoo.com; ztekiner@gazi.edu.tr; mturker@gazi.edu.tr; Radu.Orban@stm.utcluj.ro Received June 16, 2010; Revision accepted Oct. 22, 2010; Crosschecked July 19, 2011 Abstract: Mechanical and physical properties, such as tensile strength, elongation at break, modulus of elasticity, Shore D hardness, melt flow rate (MFR), and electrical and thermal conductivities of composites with high density polyethylene matrix reinforced with Al powders were investigated experimentally. Measurements of the mechanical and physical properties were performed up to a reinforcing component concentration of 30% volume Al powder and compared with mathematical models from the literature. The obtained results have shown that experimental data were in good agreement with theoretical data. The ultimate tensile strength (UTS) and elongation at break decreased with increasing Al powder content, which was attributed to the intro- duction of discontinuities in the polymer structure, and modulus of elasticity increased with increasing Al content. The composite preparation conditions allowed the formation of a random distribution of metallic particles in the polymer matrix volume for system high density polyethylene-Al (HDPE-Al). There was a cluster formation of Al particles at higher Al contents in the polymer matrix. Electrical and thermal conductivity values of HDPE-Al composites were higher than pure HDPE values. Key words: Polymer composite, Mechanical properties, Melt flow rate (MFR), Thermal conductivity, Electrical conductivity doi:10.1631/jzus.A1000286 Document code: A CLC number: TB32 1 Introduction Metal powders play an important role in the production of polymeric materials. In addition to cost saving (Bader, 2002; Park et al., 2009), other value- added properties are gained through the use of fillers. Metal powders can improve optical and mechanical (Han and Jang, 1999), thermal (Progelhof et al., 1976), and electrical (Lux, 1993) properties of polymer materials. Polymers can be modified with metallic powders for more specific uses such as anti- fouling compounds, corrosion-resistant paints, and maintenance products such as cold-poured steel and tooling. Metal filled polymer composites are often used as heating elements, temperature-dependence resistors and sensors, self-limiting electrical heaters and switching devices, and antistatic materials for electromagnetic interference shielding of electronic devices, etc. They are much cheaper than metals. Some of these materials are multifunctional, envi- ronmentally friendly, offer better corrosion resistance than metals and, in most cases, require only one-step processing, compared to the great number of steps involved in metal processing. The conductivity of polymer composites that contain dispersed conductive fillers depends on many factors such as the size and the shape of the filler particles, their spatial distribution within a polymer matrix, and the interactions between the filler surface and the polymer matrix (Gavarri et al., 1999; Kovacs et al., 2007). Additionally, their electrical and thermal conductivity levels can be designed in order to satisfy the various requirements of the end users. The Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering) ISSN 1673-565X (Print); ISSN 1862-1775 (Online) www.zju.edu.cn/jzus; www.springerlink.com E-mail: jzus@zju.edu.cn ‡ Corresponding author © Zhejiang University and Springer-Verlag Berlin Heidelberg 2011