Machining of Metal Matrix Hybrid Nanocomposites with CNC milling method


Karabacak A. H. , Çelebi M.

1st International Conference on Engineering and Applied Natural Sciences, Konya, Turkey, 10 - 13 May 2022, pp.457-461

  • Publication Type: Conference Paper / Full Text
  • City: Konya
  • Country: Turkey
  • Page Numbers: pp.457-461
  • Karadeniz Technical University Affiliated: Yes

Abstract

In this study, an attempt was made to investigate the mechanical and machinability properties, including surface morphology, on an Al 2024 alloy-based hybrid nanocomposite containing varying ratio of SiC and B4C. Hybrid nanocomposites with different reinforcement ratios were produced by powder metallurgy method. First, the matrix and reinforcement powders were subjected to mechanical alloying in a high-energy ball mill under argon atmosphere for 8 hours. Then, the obtained nanocomposite powders were sintered at 560C under 500MPa for 3 hours with the help of a hot press. The hardness values obtained before and after the machining of the composites processed with the machining process such as the Computer Numerical Controlled (CNC) milling process are presented in the study. In addition, Material Removal Rate (MRR) and Surface Roughness (SR) values were also investigated. The machined surface formed by the machining process was examined and the surface quality for each hybrid nanocomposite was discussed. Energy Distribution Spectroscopy (EDS) mapping analysis is performed on machined surfaces. According to the results, the sample with the highest hardness value (162.8 BHN), the lowest MRR value (0.0298 mm3/min) and the highest surface roughness value (Ra= 6.81) after machining was obtained from 4% by weight hybrid nanocomposite. It was observed that the highest surface roughness value belonged to the unreinforced Al 2024 alloy. The reason for this is that the surface roughness increases with the addition of ceramic-based very hard reinforcements to the soft matrix. Experimental results revealed that incorporation of particles into the matrix reduces MRR and increases SR. In addition, the quality of the machined surface is evaluated and the presence of alloy and reinforced ingredients in the matrix is ensured.