A study on effect of dead metal zone on tool vibration, cutting and thrust forces in micro milling of Inconel 718

Inconel 718, a Nickel based superalloy is widely used for aerospace applications mainly due to its high temperature resistance and high strength to weight ratio. Its poor machinability is a limiting factor in commercial, cost intensive applications. This paper investigates the machinability of Inconel 718 in high speed drilling. The impact of the material on thrust forces, torque and chip microstructure have been measured at four different cutting speeds – 19, 27,43 and 67 m/min. The high tensile strength coupled with low thermal conductivity compounds the machining process. The thrust forces decrease with cutting speed, but the torque fluctuates at intermediate cutting speeds. Chip formation is continuous across cutting speeds, with thin cross sections and evidence of saw tooth edges. Inconel work hardens more than titanium alloys and shows good ductile to brittle transition at low temperatures creating chips of lesser length as observed using scanning electron microscopy.

Download Full-text

Effects of Process Parameters On Tool Vibration And Force Transmissibility In High-Speed Micro-Milling Machine

10.21203/rs.3.rs-952762/v1 ◽

2021 ◽

Author(s):

Chitransh Singh ◽

Arnab Das ◽

Vivek Bajpai ◽

Madan Lal Chandravanshi

Keyword(s):

Process Parameters ◽

High Speed ◽

Pure Titanium ◽

Cutting Speed ◽

Micro Milling ◽

Depth Of Cut ◽

Commercially Pure Titanium ◽

Axial Thrust ◽

Tool Vibration ◽

Radial Thrust

Abstract High-speed micro-milling is an emerging technology used to produce micro and miniaturized products with smooth surface finish and high dimensional precision. However, tool vibration is a major problem in micro-milling as it directly affects the product accuracy, surface quality and tool life. Inappropriate selection of process parameters increases radial and axial thrust as well as force transmitted to structure during micro-machining which results in rapid tool vibration. This work focuses on the experimental investigation of process parameters (cutting speed and depth of cut) in order to reduce tool vibration due to axial and radial thrust in high-speed micro-milling. The tool used in this experiment is a 2-flute end mill cutter (1 mm cutter diameter) and workpiece is a commercially pure titanium (CpTi) plate. The operation was performed at different depth of cut and varying cutting speeds keeping the chip load constant. Vibration signals were acquired and processed to obtain the vibration thrust of the tool and the force transmitted to the structure. The results indicated that as the depth of cut and cutting speed increases, both axial as well as radial thrust decreases leading to lower vibration amplitude of the cutting tool and reduction in force transmitted to the machine structure.

Download Full-text

Characteristics of Tool Vibration in Ultrasonic Vibration Cutting

Journal of the Japan Society of Precision Engineering ◽

10.2493/jjspe1933.45.1449 ◽

1979 ◽

Vol 45 (540) ◽

pp. 1449-1454

Author(s):

Yoshio TANAKA ◽

Mamoru IDO ◽

Seizo OMAE ◽

Katsumi MIZUTANI

Keyword(s):

Ultrasonic Vibration ◽

Tool Vibration ◽

Vibration Cutting ◽

Ultrasonic Vibration Cutting

Download Full-text