An ALE approach for the chip formation process in high speed machining with transient cutting conditions: Modeling and experimental validation

The productivity of machining centers is influenced inherently by the quality of NC programs. To evaluate productivity, first an effective feedrate factor and a productivity evaluation factor are proposed. It has been found that in high-speed machining, these two factors depend on a kinematic factor which is a function of (1) command feedrate, (2) average per-block travel of the tool, (3) moving vectorial variation of the tool, and (4) ac/deceleration or time constants. Then an NC program simulator has been developed to evaluate productivity. With the simulator, the machining time can be calculated accurately and the cutting conditions can be extracted. Finally, three NC programs were implemented on high-speed machining centers and analyzed by the simulator. It was found that in mold and die machining, the productivity can be improved by increasing the acceleration and average travel and reducing the vectorial variation of the tool rather than the command feedrate. [S1087-1357(00)01303-4]

Download Full-text

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

Tribology ◽

10.1115/imece2005-80640 ◽

2005 ◽

Cited By ~ 1

Author(s):

Alexander Bardetsky ◽

Helmi Attia ◽

Mohamed Elbestawi

Keyword(s):

Fracture Mechanics ◽

Tool Wear ◽

Model Calibration ◽

High Speed ◽

Cutting Conditions ◽

Depth Of Cut ◽

High Speed Machining ◽

Wear Model ◽

Wide Range ◽

Cast Alloys

Experimental study has been carried out 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. The experimental setup and force measurement system are described. The 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. The prediction errors were found to be less then 7%, 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.

Download Full-text

Grain size influence on chip formation in high-speed machining of pure iron

The International Journal of Advanced Manufacturing Technology ◽

10.1007/s00170-020-05512-6 ◽

2020 ◽

Vol 108 (5-6) ◽

pp. 1357-1366

Author(s):

Xiuxuan Yang ◽

Bi Zhang ◽

Qian Bai ◽

Meng Zheng ◽

Jingang Tang

Keyword(s):

Grain Size ◽

Chip Formation ◽

Pure Iron ◽

High Speed ◽

High Speed Machining ◽

On Chip

Download Full-text

Mechanism of Chip Formation Process at Grinding

MATEC Web of Conferences ◽

10.1051/matecconf/201929709002 ◽

2019 ◽

Vol 297 ◽

pp. 09002

Author(s):

Vyacheslav Shumyacher ◽

Sergey Kryukov ◽

Olga Kulik ◽

Xavier Kennedy

Keyword(s):

Formation Process ◽

Chip Formation ◽

High Speed ◽

Cutting Speed ◽

Dimensional Accuracy ◽

Processing Parameters ◽

Abrasive Grain ◽

Wave Heating ◽

High Speed Grinding

The mechanism of chip formation process at grinding is described, which involves a high-speed interaction of abrasive grain and metal, which leads to a concentration of thermal energy in front of the dispersing element (grain), causing a locally concentrated shift in the metal microvolume. In “abrasive grain -metal” contact a dissipative structure is formed which existence is supported by exchange of energy and substance with environment. Due to shock compression of the metal microvolume with abrasive grain, shock-wave heating is realized, initiating emission of electrons ionizing the lubricating cooling fluid in the zone of formation of side micro-scratches left by abrasive. The results obtained in the course of the research can be used to explain the mechanisms of chip formation, as well as the course of the physical and mechanical processes occurring on the surface layers of the grinded workpieces. By controlling chip formation processes at high-speed grinding, by optimally selecting the appropriate ratios between cutting speed and other processing parameters, a reduction in process thermal density can be achieved, which, with the highest productivity, will allow to obtain the required quality of the surface layer of the workpieces and a given dimensional accuracy.

Download Full-text