Rotary ultrasonic drilling of polyetherimide composite to enhance the surface roughness and MRR: Experimental investigations and statistical approach

Polyetherimide Composite (PEC) is among the least dense and most compliant materials which possesses the properties of high heat resistance, durability, resistant to wear and corrosion as well as better tribological characteristics. These outstanding properties lead to its diverse applications in automobiles, aerospace, robots, sports equipment. PEC is machined by the conventional machining techniques like cutting, drilling, power hacksaw etc. Some of the limitations observed in conventional machining of these such as tool jamming, damage to surface topology, and fibres. To overcome the aforesaid limitations, in this work attempts to introduce rotary ultrasonic drilling (RUD) as viable option for machining of PEC. This work carries out the investigational study of input control factors on material removal rate (MRR) and surface roughness (SR). The outcomes of the study reveal that the with right selection of drilling control factors, better quality holes with superior topography as compared to conventional drilling, good surface finish, small exit chip sizes, low overcut errors are obtained. Interacting levels of higher spindle speed and a lower feed rate generated better surface characteristics. While drilling with the RUD as compared to normal drilling, there is a drop of 59.01 % at 550 rpm and 60 .9 % at 2550 rpm in SR.