Micro-cutting force model of micro-jet induced by cavitation collapse in the ultrasonic field at micro-nano scale

Abstract The micro-jet is the main mechanism of cavitation on materials. More and more ultrasonic cavitation assisted machining uses the micro-jet effect in the industrial field. In this paper, the micro-jet impact is considered as the micro cutting process. To deeply analyze the micro cutting mechanism of micro-jet, the size effect of materials was considered, and the micro cutting force model of micro-jet was established and solved based on the spherical indentation test theory and the strain gradient plasticity theory. The results showed that the micro cutting force and impact pressure of micro-jet with size effect are larger than those without size effect, and the micro cutting force of single micro-jet is within 2.35 N. The micro cutting force of micro-jet increases exponentially with the increase of pit radius, but only slightly increases with the increase of pit depth. When the size effect is considered or not, the impact pressure of micro-jet is 1616-2922 MPa or 1615-1980 MPa, respectively. The increase ratio of micro cutting force with size effect is , which can directly reflect the strength of size effect. The size effect is more obvious when the pit size is smaller, and the maximum increase ratio is 47.54%.The increase ratio increases nonlinearly with the decrease of pit radius and increases with the increase of pit depth. It has a strong correlation with pit radius and pit depth. This paper can provide a new theoretical viewpoint and support for the quantitative description of cavitation effect in ultrasonic assisted machining.

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Study on mathematical model of cutting force in micromachining

International Journal of Modeling Simulation and Scientific Computing ◽

10.1142/s1793962315500397 ◽

2015 ◽

Vol 06 (04) ◽

pp. 1550039

Author(s):

Zhen Yu ◽

Quan-Jie Gao ◽

Ding-Fang Chen

Keyword(s):

Cutting Force ◽

Cutting Tool ◽

Small Deformation ◽

Surface Friction ◽

Force Model ◽

Gradient Plasticity ◽

Cutting Force Model ◽

Cutting Depth ◽

Micro Cutting ◽

Extrusion Mechanism

With the development of micromachining technology, it is very important to study the mechanism of micromachining, determine the micromachining parameters and ensure the products’ quality during the micromachining process. Combined with the micro-mechanism between tool and workpiece during micromachining process, the sources of the micro-cutting force were analyzed, the micro-cutting physical model was constructed, and the microstress model interacted between the cutting arc edge of the tool and the material of the workpiece was analyzed. Combined with the surface friction and elastic extrusion mechanism between the cutting tool and workpiece, the micro-cutting force model was constructed from two aspects. The micro-cutting depth is deeper than the minimum cutting depth and the micro-cutting depth is shallower than the minimum cutting depth, then the minimum cutting depth value was calculated. Combined with the dislocation properties and microcrystal structure of workpiece’s material, the internal stress of the micromachining force model based on the gradient plasticity theory was calculated, and the force model of the micro-cutting process was studied too. It is significant to control the precision of micromachining process during the micromachining process by constructing the micromachining process force model through studying the small deformation of the material and the mechanism of micromachining.

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