Reliability analysis of the cutting tool in plasma-assisted turning and prediction of machining characteristics

ABSTRACT

Heat-assisted machining (HAM) is an alternative method for the successful machining of difficult-to-cut aerospace superalloys. However, the tool wear progression in HAM has been substantially affected by the workpiece external heating temperature along with the machining parameters. It is of great importance to precisely estimate the tool wear progression and reliability of the cutting tool operated in HAM to enhance the machining efficiency and economics. Hardened AISI4340 alloy steel was machined under plasma-arc heating conditions with WC cutting tools. The experimental results reviled that for 200°C of preheating temperature, the surface roughness noted as 2.03µm and tool life as 870s. While at 600°C, the surface roughness as 1.68µm, and tool life extended to 1885s to reach the set threshold value of 0.4mm flank wear. Notch wear as dominant tool wear mechanism at 200°C and 400°C, while it is diffusion wear at 600°C. On the establishment of stochastic tool life distribution and reliability models, tool lives measured at all heating conditions followed a Weibull distribution. Empirical models for tool wear, surface roughness, and material removal rate were postulated and validated statistically as-well-as experimentally. The derived reliability and empirical models can be used to predict the machining characteristics to enhance its performance.

KEYWORDS:

• Plasma heat-assisted turning
• mechanism of tool wear
• tool life reliability models
• surface roughness
• metal removal rate
• empirical modelling
• experimental validation

Article highlights

• Heat-assisted turning process was performed with the plasma arc heat source.

• The significance of workpiece heating temperature on tool wear progression as-well-as machined surface roughness were analysed.

• Stochastic tool life distribution and reliability models were established for varying conditions of workpiece heating temperatures.

• Empirical models for tool wear, surface roughness, and material removal rate were postulated and validated statistically as-well-as experimentally.

Disclosure statement

No potential conflict of interest was reported by the author.

Additional information

Notes on contributors

Thella Babu Rao

Dr. Thella Babu Rao is currently working as an Assistant Professor in the Department of Mechanical Engineering, National Institute of Technology Andhra Pradesh, India. His research interests are: machining technologies,  modeling and simulation of manufacturing processes, development and characterization of composite materials.