Comprehensive study on effect of orthogonal turn-milling parameters on surface integrity of Inconel 718 considering production rate as constrain

Abstract

Round bars made of Inconel 718 are widely used in aerospace industries due to their excellent properties of working at harsh environment. However, machinability of this alloy by conventional turning process results in excessive tool wear and poor surface integrity. The former increases the production cost and latter reduces the fatigue life. In the present paper, interrupted cutting of Inconel 718 round bars was introduced as an effective way for enhancing the life time. Turn-milling as newly emerging cutting technology was utilized here to machine cylindrical samples of Inconel 718. Effect of process factors such as tool rotational speed, workpiece rotational speed, feed rate and eccentricity was analyzed on surface roughness and residual stress. The obtained results showed that the feed rate is most influential parameter that determines value of surface roughness and residual stress and. Furthermore, by considering production rate as a constraint, it was logically discussed that a setting of 1000 rpm cutter speed, 300 rpm work rotational speed, 0.12 mm/rev feed rate and 0.2 mm eccentricity can guarantee maximum production rate as well minimum surface roughness and tensile residual stress.

Keywords

• Turn-milling
• Surface integrity
• Inconel 718
• Experimental study