Use of Used Graphite Electrodes as Metal Matrix Composites Reinforcement

The work presents the effect of the addition of graphite from recycled graphite electrodes on the mechanical properties of metal matrix composites (MMC) based on the AlMg10 alloy. A composite based on the AlMg10 alloy reinforced with natural graphite particles was also tested. Further, tests of the mechanical properties of the AlMg10 alloy were performed for comparative purposes. Composites with a particle content of 5, 10 and 15 percent by volume were produced by adding introduction of particles into the liquid matrix while mechanically mixing molten alloy. The composite suspensions were gravitationally cast into metal molds. Samples for the Rm, R0.2, A and E tests were made from the prepared castings. Photos of the microstructures of the materials were also taken. The research shows that the addition of graphite to the matrix alloy causes minor changes in tensile strength (Rm) and yield strength (R02), regardless of the type of graphite used. The results of the relative elongation tests showed that the introduction of graphite particles into the matrix alloy had an adverse effect on the elongation values in the case of each of the tested composites. The introduction of graphite particles into the AlMg10 alloy significantly increased the Young’s modulus value, both in the case of composites with flake graphite (natural) and graphite from ground graphite electrodes.