Characterization of compression strength of granite-epoxy composites using design of experiments

Abstract

This paper presents a processing study of the polymer matrix composite (PMC) developed with an epoxy polymeric matrix reinforced with particulate ceramic granite. This PMC composite has been reported to be used as structural parts of machine tools and Coordinate Measuring Machines due to its superior vibration damping characteristics and reduced processing cycle over cast iron. The investigated processing variables were epoxy content and particle size and the mechanical characterization was carried out by compressive tests. Rejects of granite with particle size smaller than 500 µm were prepared by crushing, milling and classification operations. The powder was mixed with different compositions of epoxy resin, between 15 and 20% in weight. An experiment was planned and executed according to the Factorial design technique using two variables at two levels. The obtained cylindrical samples were submitted to compressive strength tests and the results showed a maximum resistance of 114.23 MPa at 20 wt. (%) epoxy, value close to that of the literature.

Behavior of granite-epoxy composite beams subjected to mechanical vibrations

“…In Brazil, there is no company that produces this material, even though there exist in the market Machine Tools built up based upon synthetic granite. Other applications, besides Machine Tools, are the fabrication of optical equipments such as optical microscopes, loupes, image capturing systems, telescopes and laser instruments for medical and dental applications 4 . The size, homogeneity, the ceramic particles purity and the polymers viscosity are some of the processing variables that affect the properties of these composites.…”

“…The polymeric resin viscosity during the mixing step with the granite greatly affects the composite`s structural homogeneity, being difficult the mixing of ceramic particles with a polymeric viscous resin. Defects caused by agglomerated particles of ceramic granite (clusters) can result in reduced composite`s resistance limit 4 . The damping capacity of a material is related to the dissipation of vibration energy in its internal structure, which is constantly supplied by the relative motion and friction of the parts during the operation of a Machine Tool.…”

“…Brazilian researchers investigated granite-epoxy composites processing 4,[9][10][11][12][13] . Results concerning compression resistance, equivalent to those found in similar foreign commercial materials, were obtained by studying processing variables such as particulate granite rates with different particle size and mass of granite and epoxy.…”

Analysis of effective thermal conductivity for mineral cast material structures with varying epoxy content using TPS method

“…It is observed that effective thermal conductivity decreases with increase in epoxy content in the mixture. Neglecting the effect of size of crushed granite particles on effective thermal conductivity 16 , the trend observed could be due to the presence of epoxy resin having very low thermal conductivity (0.363 W/m. K), between the granite particles.…”

“…The range for study is selected from the literature which indicates that, the preferable range of volume fraction of epoxy content in a mixture is 12%-20%, considering the strength and mechanical properties of the structure developed 15,16 . The mixtures selected for analysis in this study are given in Table 1.…”