The aim of the work was to achieve assumed gradation of hard coal particles distribution in epoxy matrix and thus gradation of properties. It was done by proper selection of compounds composition and conditions of the gradation formation. The graded composites were produced using centrifugal casting. Two types of epoxy resins as a matrix and two types of hard coal of various granulation as a filler were used. Samples in the form of bushings with radial carbon filler gradation were produced by changing filler type, its volumetric content and parameters of centrifugal casting. The first part of the paper presents results of graded materials structure investigations. The microscopic observations of the structure of composites prepared according to elaborated experimental program show that the composites are characterized by continuous change of the filler particles content in radial direction, so they can be classified as graded materials. Results also show that gradation of particles content and thus gradation of properties may be planned and foreseen when mechanisms of gradation formation are known.
PiousCVThomasS2 – polymeric materials – structure, properties, and applications. In: IzdebskaJThomasS (eds). Printing on Polymers Fundamentals and Applications, USA: William Andrew Publishers, 2015, pp. 21–39.
13.
GibsonRF. A review of recent research on mechanics of multifunctional composite materials and structures. Compos Struct2010; 92: 2793–2810.
14.
ZhuY-BNingN-YSunY. A new technique for preparing a filled type of polymeric gradient material. Macromol Mater Eng2006; 291: 1388–1396.
15.
Mamunya YePDavydenkoVVPissisP. Electrical and thermal conductivity of polymers filled with metal powders. Eur Polym J2002; 38: 1887–1897.
16.
ClaussenaKUGiesaRSchmidtH-W. Longitudinal polymer gradient materials based on crosslinked polymers. Polymer2014; 55: 29–38.
17.
NardiTCanalLPHausmannM. Stress reduction mechanisms during photopolymerization of functionally graded polymer nanocomposite coatings. Prog Org Coat2015; 87: 204–212.
18.
MüllerMHuynhQ-UUhlmannE. Study of inkjet printing as additive manufacturing process for gradient polyurethane material. Product Eng2014; 8: 25–32.
19.
Kurzeja L, Galy J and Sautereau H. Epoxy networks filled with coal particles of different rank. In: Proceedings of international conference “Eurocarbon’98”, Strasbourg, France, 5–9 July 1998, pp.401–402. Philadelphia PA: Elsevier.
20.
Kurzeja L, Galy J and Sautereau H. Synthesis and properties of coal-filled epoxy networks. In: Proceedings of international conference eurofillers’99, 6–9 September, 1999, Lyon – Villeurbanne, France.
21.
KurzejaLSzelugaUGalyJ. Effect of coal on the rheological and mechanical properties of epoxy matrix. Macromol Symp2003; 194: 169–174.
22.
RhodesM. Introduction to particle technology, 2nd ed. England: John Wiley & Sons Ltd., 2008.
BansalRK. A textbook of fluid mechanics, New Delhi: Laxmi Publications, 2008.
25.
MunsonBRYoungDFOkiishiAT. Fundamentals of fluid mechanics, 4th ed. New York, NY: John Wiley and Sons, Inc, 2002.
26.
HollandFABraggR. Fluid flow for chemical engineers, 2nd ed. Oxford: Butterworth-Heinemann Publisher, 1995.
27.
CutlibMBShachamM. Problem solving in chemical and biochemical engineering with POLYMATH,™ Excel, and MATLAB®, Upper Saddle River, NJ: Prentice Hall, 2007.
28.
HashmiSAR. Attaining a controlled graded distribution of particles in polymerizing fluid for functionally graded materials. J Appl Polym Sci2006; 99: 3009–3017.
29.
WatanabeYKawamotoAMatsudaK. Particle size distributions in functionally graded materials fabricated by the centrifugal solid-particle method. Compos Sci Technol2002; 62: 881–888.
30.
HashmiSRADwivediUK. Estimation of concentration of particles in polymerizing fluid during centrifugal casting of functionally graded polymer composites. J Polym Res2007; 14: 75–81.
31.
FunabashiM. Gradient composites of nickel coated carbon fibre filled epoxy resin moulded under centrifugal force. Compos Part A1997; 28: 731–737.
32.
ButcherRJRousseauC-ETippurHV. A functionally graded particulate composite: preparation, measurements and failure analysis. Acta Materialia1999; 47: 259–268.
33.
HashmiSARDwivediUK. Simulation of compositional profile in functionally graded materials. Polym Eng Sci2006; 46: 1660–1666.
34.
Stabik J and Szczepanik M. Surface resistivity of carbon epoxy composites centrifugally cast (monograph). Gliwice: Engineering Polymers and Composites, 2010, pp.385–392 (in Polish).
35.
StabikJChomiakM. Influence of casting velocity on surface resistivity of epoxy-hard coal graded composites. Arch Mater Sci Eng2011; 47: 48–56.
36.
MathewsPG. Design of experiments with MINITAB, Milwaukee: ASQ Quality press, 2005.
37.
GibbonsNM. Experimental statistics, Mineola, New York: Dover Publications, 2005.
38.
StabikJChomiakMSuchońŁ. Methods of sample preparation gradient polymer material for microscopic examination. Plast Process2012; 4: 356–360. in Polish.
39.
ChrapońskiJMalińskiMSzalaJ. Stereological characteristics of the simulated computer model structures of functionally graded materials. Mater Eng2006; 27: 568–571. in Polish.
40.
HunterRJ. Foundations of colloid science, Oxford: Oxford University Press, 2001.
41.
RichardsonJFHarkerJHBackhurstJR. Coulson and Richardson’s chemical engineering – particle technology and separation processes, Amsterdam: Elsevier Ltd., 2002.
