A Fracture Mechanics Approach to the Prediction of Tool Wear in Dry High Speed Machining of Aluminum Cast Alloys—Part 2: Model Calibration and Verification

Abstract

Background. Aluminum alloys are extensively used in the automotive industry and their utilization continues to rise because of the environmental, safety and driving performance advantages. Experimental study has been carried out in this work to establish the effect of cutting conditions (speed, feed, and depth of cut) on the cutting forces and time variation of carbide tool wear data in high-speed machining (face milling) of Al–Si cast alloys that are commonly used in the automotive industry. Method and Approach. The experimental setup and force measurement system are described. The cutting test results are used to calibrate and validate the fracture mechanics-based tool wear model developed in part 1 of this work. The model calibration is conducted for two combinations of cutting speed and a feed rate, which represent a lower and upper limit of the range of cutting conditions. The calibrated model is then validated for a wide range of cutting conditions. This validation is performed by comparing the experimental tool wear data with the tool wear predicted by calibrated cutting tool wear model. Results and Conclusions. The maximum prediction error was found to be 14.5%, demonstrating the accuracy of the object oriented finite element (OOFE) modeling of the crack propagation process in the cobalt binder. It also demonstrates its capability in capturing the physics of the wear process. This is attributed to the fact that the OOF model incorporates the real microstructure of the tool material. The model can be readily extended to any microstructure of Al–Si workpiece and carbide cutting tool material.

Cyber–Physical Systems for High-Performance Machining of Difficult to Cut Materials in I5.0 Era—A Review

“…The two main strategies for simulating crack propagation in cemented carbides are the simulation of small crack progress based on crack tip displacement (CTD) analysis and mesoscale crack propagation simulation based on continuum damage mechanics (CDM). Crack propagation analysis based on the CTD criterion is mainly applied for one cycle stress loading conditions [121].…”

“…An essential aspect of a cyber-physical machining system is to predict the tool life and adjust the cutting conditions to utilize the full potential of the tool while avoiding excessive wear rates. A wear model developed based on the finite element of crack propagation in the tool microstructure can determine the wear status more accurately, as presented in [121,126]. In this study, the flank face of the tool was partitioned based on the average size of the WC grains of the tool material, as shown in Figure 8a.…”

High-Performance Machining System: Process Optimization for a Cyber-Physical System – a Review

“…The state of tool wear has a significant impact on machining optimization objectives such as energy consumption and product quality [56]. Tool wear mechanisms can be attributed to mechanical [88,89], thermal [90,91], and chemical [92,93], making the wear phenomenon a complex modelling problem. Traditionally, direct tool wear evaluation techniques such as using a microscope, CCD (charged-coupled device) camera, or laser beam have been used to assess the status of tool wear.…”

“…The mechanically activated wear can be simulated based on the finite element simulation of crack propagation in the tool material [88,89,293,294]. In order to model the temperature-activated wear mechanism, it is important to determine the temperature distribution at the interfaces of the tool-chip and tool-workpiece.…”

“…The two main strategies to simulate the crack propagation in cemented carbides are the simulation of small crack progress based on crack tip displacement (CTD) analysis and the mesoscale crack propagation simulation based on the continuum damage mechanics (CDM). The crack propagation analysis based on CTD criterion is mainly applied for one cycle stress loading conditions [88,89,289].…”