Papers by Author: Ahmed A.D. Sarhan

Abstract: In this study, an experimental investigation was conducted to determine the effects of cutting speeds and feed rates on surface roughness in turning of the Al %11Si and Al-11%Si-1% Bi die cast alloys. Experimental trials carried out on a CNC machine using coated carbide inserts (PVD). Three different cutting speeds, 70, 130 and 250 m/min and three feed rates 0.05, 0.1 and 0.15 mm/rev were used with a 0.15 mm constant depth of cut for all experiments. Additionally scanning electron microscope (SEM) was employed to clarify the different types of silicon morphology. Results revealed that surface roughness increased with increasing feed rate from 0.05 to 0.15 mm/rev and decreased with increasing cutting speed from 70 to 250 m/min. The result showed that workpiece containing Bi had the best surface roughness with lamellar silicon shape in comparison with aluminium-silicon with flake-silicon shape.

Abstract: In recent years, the energy efficiency improvement has become significant due to rapid consumption of world's energy resources. Particularly in manufacturing industry, hard turning process is one of the most fundamental metal removal processes that require huge power consumption and it could be improved in term of energy usage by many alternatives. At the same time, the improvement in term of machined surface quality is become a need since it would reflect appearance, performance and reliability of the products. As for example in the CNC machining field, one of the solution for this issue is by increasing the effectiveness of the existing lubrication systems as it could improve the machined surface quality, reduce the power required to overcome the friction component in batch production of machining process and reduce the oil consumption. The effectiveness of the lubrication system could be improved by introducing the nanobase lubrication system for much less power consumption as the rolling action of billions units of nanoparticle in the tool chip interface could reduce the cutting forces significantly. In this research work, the possibility of using SiO₂ nanobase lubrication system is investigated to reduce the machining power consumption as well as improving surface quality in hard turning process of AISI4140.