Engineering and Technology Journal

Electrical discharge machining (EDM) is one of the most common non-traditional processes for the manufacture of high precision parts and complex shapes. The EDM process depends on the heat energy between the work material and the tool electrode. This study focused on the material removal rate (MRR), the surface roughness, and tool wear in a 304 stainless steel EDM. The composite electrode consisted of copper (Cu) and silicon carbide (SiC). The current effects imposed on the working material, as well as the pulses that change over time during the experiment. When the current used is (8, 5, 3, 2, 1.5) A, the pulse time used is (12, 25) μs and the size of the space used is (1) mm. Optimum surface roughness under a current of 1.5 A and the pulse time of 25 μs with a maximum MRR of 8 A and the pulse duration of 25 μs.

This work aims to a development of mechanical properties of PMMA that is utilized in denture material, by using two types of polymers; blends (PMMA:2%NR) and (PMMA:2%SR) as a matrix materials strengthen with natural nanoparticles from the pomegranate peel powder (PPP) that were added at different weight fractions (0.0, 0.1%, 0.3%, 0.5% and 0.7%). Two groups of bio nanocomposites specimens were prepared, using (Hand Lay-Up) method. Experimental tests were carried out on surface roughness, hardness and wear rate as well as analyzing of FTIR test. The minimum values of surface roughness and wear rate were reached 1.51 nm and 0.317×10-8 g/cm respectively for polymer blend nanocomposite ((PMMA:2%NR): 0.7% PPP). Whereas, the maximum value of Shore D hardness reached 90 for the same sample of nanocomposites. According to these results, it can be a concluded that the addition of Nano pomegranate powder and natural rubber can develop the mechanical properties of PMMA material used in medical applications.