Effect of ultrasonic sound wave on machinability parameters during turning operation of mild steel

Abstract

This project aims to investigate the effects of ultrasonic sound signal on the machinability control of mild steel during turning operation. The machinability responses include tool wear, surface roughness, temperature, chip morphology. A control experiment was also done where no ultrasonic sound is applied at all. Turning is a form of machining which is used to create rotational parts by removing unwanted material. In turning process sometimes tool life, machined surface quality is damaged because of formation of chatter. Chatter causes unwanted excessive vibratory motion in between the tool and the work-piece causing adverse effects on the product quality and machine-tool and tool life. In addition to the damage of the work-piece surface due to chatter marks, the occurrence of severe chatter results in many adverse effects, which include poor dimensional accuracy of the work-piece, reduction of tool life, and damage to the machine. The main purpose of this research is to send sound signal in the cutting processes and to investigate the effect of ultrasonic sound waves signal during turning operation on the machinability responses such as tool wear, surface roughness, and chip behavior. The ultrasonic sound wave that has been used is 40 KHZ. There are two ultrasound modules from where that sound wave has formed. The results show clear improvement in the machinability responses during the turning process which include significant reduction in the tool wear, improvement in surface quality, and decrease in the serration behavior of chips. The quality of the finished product along with the productivity play a significant role in today‟s manufacturing market. From customers‟ viewpoint quality is very important because the extent of quality of the produced item influences the degree of satisfaction of the consumers during usage of the product. Every manufacturing industry aims at producing a large number of products within relatively lesser time. But it is felt that reduction in manufacturing time may cause severe quality loss. However application of ultrasonic sound can result in the surface quality of the product conditioned by the cutting parameter. The surface quality during ultrasound cutting is significantly improved than that obtained from normal cutting. The 7 frequency change of ultrasonic sound also has some impact on the surface quality which is mainly because of the chip adhering to the tool during cutting operation. Behavior of chips indicate the vibration nature of the machine and the tool. Chips produced during cutting operation have some teeth in its cross section which have been viewed with microscope to find out the effect of these ultrasonic sounds on the serration behavior. Here also it is clearly shown that the teeth produced during ultrasound cutting are smaller in size whereas they are much bigger for normal cutting. This phenomenon indicates that application of external ultrasonic sound reduces the vibration of the machine tool. The increase of the force increases the temperature of the work piece and the tool insert. Having difficulties in measuring the temperature of the work piece, I have measured the temperature of the insert near the cutting junction with the aid of a thermocouple. The project is successful in establishing an improvement in tool life with the application of ultrasonic sound on the tool insert during turning operation.