International Conference on Mechanical, Industrial and Energy Engineering 2014 26-27 December, 2014, Khulna, BANGLADESH * Corresponding author. Tel.: +6174631 1338 E-mail address: Mainul.Islam@usq.edu.au ICMIEE-PI-140137 Compressive Properties of Ceramic Microballoon Syntactic Foams Zulzamri Salleh 1,2 , Md Mainul Islam 2* and Jayantha Ananda Epaarachchi 1 1 Centre of Excellence in Engineered Fibre Composites and School of Mechanical and Electrical Engineering, Faculty of Health, Engineering and Sciences, University of Southern Queensland, Toowoomba, Queensland 4350, AUSTRALIA 2 Universiti Kuala Lumpur, Malaysian Institute of Marine Engineering Technology (MIMET), 32200, Lumut Perak, MALAYSIA ABSTRACT In this paper, fabrications of vinyl ester syntactic foams with different contents of ceramic microballoons or microspheres were prepared using the open mould method for compression specimens. The effects of the ceramic microballoons on the mechanical properties, particularly compressive properties were investigated. The results show that the syntactic foams with vinyl ester matrix possess strength behaviour varied with different contents of ceramic microballoons. Ceramic microballoons have an important effect on the stress-strain, mean plateau stress and strain energy absorption capacities of syntactic foams. The results also show that the content of ceramic microballoons in vinyl ester syntactic foams should be controlled in order to obtain a good combination of compressive strength and energy absorption capacities. The reasons are discussed here in details. Keywords: Syntactic foams, ceramic microballoons, compressive properties, content. 1. Introduction Ceramic microballoon or microspehere is defined as an inorganic nonmetallic polycrystal sphere or approximate sphere with the size of micron [1]. Ceramic microballoon is widely used in the medical industry, chemical and nuclear industry and also in the defence industry. From the literature review, ceramic microballoons are widely used combining with Aluminium matrix. It is not only limited use for aviation, but also used for civil industry and automotive industry [1]. This metallic foam is defined as metal-matrix syntactic foams (MMSFs) with the first production in 1990s [2]. The structural engineering is always desired for the better mechanical properties of material such the compressive behaviour of the products. For example stronger and lighter materials such as syntactic foams are better choice for both of the mechanical behaviours particularly for structural engineering. In the previous works, many researchers were interested on the properties of the foams particularly characteristic on the compressive strength and the absorbed energy. The investigation on the effects of the microballoon size on the compressive strength is very beneficial for future engineering [3]. From the research it was found that smaller microspheres ensure higher compressive strength because they contain fewer flaws in their microstructure than the larger ones. While Palmer et al. proved that larger microspheres contain more porosity in their walls and more flaws in their microstructure than the smaller ones [4]. From the literature review it was also found that the chemical reaction contributed detrimental effect on the load transfer during mechanical testing [5]. Balch et al. found that the microspheres have at least the same importance in the syntactic foams as the matrix material [6]. The fracture strength and the yield strength of the matrix determine the failure stress of the syntactic forms. Therefore, the investigation on mechanical properties, particularly compressive strength effect will be affected the quality of the microspheres and it is very important. Nevertheless, no report was published for ceramic microballoons mix with vinyl resin as matrix materials. In this study, the report will cover from the preparation of samples to the mechanical properties. The aim of this study is to investigate the distribution of the constituents in the ceramic microballoons with the different contents’ effect on the vinyl ester resin as matrix material. All these information will be beneficial and acceptable for the production of ceramic microballoon of syntactic foams. 2. Materials and Methodology Ceramic microballoons type SL75 is used in the difference weight percentages as 2.0wt.%, 4.0wt.%, 6.0wt%, 8.0wt.% and 10.0wt.% to fabricate these foams. E-spheres a ceramic bubble was supplied by Envirospheres Pty. Ltd (Australia) company are used in this study [7]. Their main parameters are provided by supplier is listed in Table 1. Table 1 Properties of ceramic microballoon.   T Compressive Strength Chemical Compositi on 45 0.40 1600- 1800 45MPa SiO 2 -60% Al2O 3 - 38% TiO 2 -2% Fig. 1 shows the SEM photo for ceramic microballoon provided by the supplier [7]. Vinyl ester resin, supplied by Norox Australia Company, is used as the matrix material. This is diglicidyl ether of bisphenol A-based resin. An amine-based MEKP is used as a hardener.