Cutting Characteristics of Hard-Brittle Materials Under Nano/Micro Groove Cutting Using a V-Shape Tool

2020 ◽  
Author(s):  
Yoshino Masahiko ◽  
Shen Hao ◽  
Yuki Nakagawa ◽  
Abdallah Abdelkawy
Keyword(s):  
Cutting Force ◽  
Plastic Flow ◽  
Brittle Materials ◽  
Rake Angle ◽  
Depth Of Cut ◽  
Critical Depth ◽  
Single Crystal Diamond ◽  
Critical Depth Of Cut ◽  
Cutting Model ◽  
Groove Cutting

Abstract The cutting characteristics and the critical depth of cut in nano/micro cutting of hard/brittle materials were investigated. A V-shaped single crystal diamond tool with a negative rake angle was used as the tool, and a cutting experiment was conducted by means of the inclined cutting test technique. The effect of rake angle on specific cutting force was also compared with V-groove cutting model based on simple shear plane. It was found that the cutting force increased and the burrs height increased as the rake angle became negative. and it was considered that the plastic flow influenced on the cutting force. It was also found that the critical cutting depth decreases with the decrease of the rake angle. The result of this experiment showed the opposite tendency to previous studies on the critical depth of cut. This is attributed to that, in the V-type tool cutting, the crack growth by increasing plastic flow is more effective than the suppress of cracks growth by increase of hydrostatic pressure.

Effects of Spindle Speed on Turning Stability

2012 ◽  
Author(s):  
Achala V. Dassanayake ◽  
C. Steve Suh
Keyword(s):  
Cutting Force ◽  
Stability Study ◽  
Spindle Speed ◽  
Depth Of Cut ◽  
Critical Depth ◽  
Force Amplitude ◽  
Speed Increase ◽  
Critical Depth Of Cut ◽  
The Times ◽  
Cutting Model

Machining stability study for rough cuts suggests that low speeds impart instability. However, bifurcated states could be staged in between with increasing speeds. Therefore it cannot be concluded that speed increase would always result in stability. Using the cutting model presented in [1] and [2], critical DOCs are seen to increase with the increase of speed. Cutting force amplitude oscillations are determined by the nonlinearity of the force, not by speed increments. While both the tool and workpiece show similar instability stages most of the times, however, when it is closer to the critical depth-of-cut, the tool reaches instability first before the workpiece does. In contrast to the observation, when DOC is less than 1.00mm, most of the times when system is unstable, only the workpiece or the tool is unstable, but not both.

Ultra-Precision Cutting of Brittle Materials with Ultrasonic Vibrated Diamond Tool

2006 ◽  
Vol 532-533 ◽  
pp. 169-172 ◽  
Author(s):  
Chun Xiang Ma ◽  
Eiji Shamoto ◽  
Li Ming Xu ◽  
Nan Liu ◽  
T. Moriwaki
Keyword(s):  
Diamond Tool ◽  
Brittle Materials ◽  
Optical Quality ◽  
Depth Of Cut ◽  
Critical Depth ◽  
Machined Surface ◽  
Ductile Cutting ◽  
Ultra Precision ◽  
Critical Depth Of Cut ◽  
Quality Surface

The influence of the ultrasonic vibrated diamond tool on the transition of ductile cutting to brittle cutting of the glasses is investigated by facing turning. It is understood that the critical depth of cut for the ductile cutting of the brittle materials is increased obviously by the ultrasonic vibrated diamond tool. The optical quality surface of the glasses is obtained, the surface roughness of which is less than0.03m. Finally, the relation between the roughness of machined surface and the cutting distance is studied experimentally.

Influence of the Grinding Wheel in the Ductile Grinding of Brittle Materials: Development and Verification of Kinematic Based Model

1999 ◽  
Vol 121 (4) ◽  
pp. 638-646 ◽  
Author(s):  
M. H. Miller ◽  
T. A. Dow
Keyword(s):  
Brittle Materials ◽  
Chip Thickness ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Critical Depth ◽  
Materials Development ◽  
Kinematic Simulation ◽  
Critical Depth Of Cut ◽  
Model Equations

Empirical evidence has shown that grinding wheel characteristics significantly affect performance in the grinding of brittle materials. In this research a grit depth of cut model was developed based on a kinematic simulation of the grinding process. The model describes the relationships between grinding wheel parameters (grit size, concentration, binder modulus) and chip thickness and area. It was corroborated by the measurement of number of cutting grits in tests using a fly wheel with small abrasive area. Based on this grit depth of cut model, the “critical depth of cut” model for the grinding of brittle materials was modified to include wheel parameter effects. The new critical depth of cut model was tested using “crossfeed” experiments. Although the theoretical and experimental results show less agreement than for the grit depth of cut model, the model equations provide guidelines for choosing wheel specifications.

Numerical Investigation of Two-Dimensional Thermally Assisted Ductile Regime Milling of Brittle Materials

2014 ◽  
Author(s):  
Jianfeng Ma ◽  
Xianchen Ge ◽  
Shuting Lei
Keyword(s):  
Chip Thickness ◽  
Rake Angle ◽  
Depth Of Cut ◽  
Critical Depth ◽  
Uncut Chip Thickness ◽  
Thermal Boundary Conditions ◽  
Orthogonal Machining ◽  
Preheating Temperature ◽  
Ductile Regime Machining ◽  
Critical Depth Of Cut

This study investigates the effects of different variables (preheating temperature, edge radius, and rake angle) on ductile regime milling of a bioceramic material known as nanohydroxyapatite (nano-HAP) using numerical simulation. AdvantEdge FEM Version 6.1 is used to conduct the simulation of 2D milling mimicked by orthogonal machining with varying uncut chip thickness. Thermal boundary conditions are specified to approximate laser preheating of the work material. Based on the pressure-based criterion for ductile regime machining, the dependence of critical depth of cut on cutting conditions is investigated using Tecplot 360. It is found that as uncut chip thickness decreases, the critical depth of cut decreases. In addition, the critical depth of cut increases as the negativity of rake angle and/or preheating temperature increase.

Micro Cutting of Glass with Multiedge Tool

2011 ◽  
Vol 5 (3) ◽  
pp. 300-306
Author(s):  
Takashi Matsumura ◽  
◽  
Tatsuya Namiki
Keyword(s):  
Cutting Force ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Optical Diffraction ◽  
Depth Of Cut ◽  
Machining Accuracy ◽  
Single Crystal Diamond ◽  
Single Crystal Diamond Tool ◽  
Critical Depth Of Cut ◽  
Glass Cutting

Glass cutting with a multiedge tool is presented to machine micro-scale grooves at high machining rates in a planning manner. The critical depth of cut at the ductile-brittle transition was measured to design the edge shape in the glass cutting tests. 13 rectangular edges 2 µm wide and 2 µm high were manufactured on a single crystal diamond tool by the focused ion beam. The cutting tests were conducted on a micro/nano-scale cutting machine, which controls the depth of cut of less than 1 µm. The glass cutting process with the multiedge tool is discussed with measuring the cutting force. The cutting force changes with the cutting mode: sliding/ploughing and cutting. Based on the measured cutting force, the compliance of the machine-tool-workpiece system, the friction coefficient of the tool on the glass surface and the specific cutting force are estimated. Then, 13 grooves 2 µm wide 0.3 µm deep were machined simultaneously in a feed of the multiedge tool. The machining accuracy was verified in optical diffraction tests.

Critical Depth of Cut and Specific Cutting Energy of a Microscribing Process for Hard and Brittle Materials

2007 ◽  
Vol 130 (1) ◽  
Author(s):  
Jiunn-Jyh Junz Wang ◽  
Yong-Yuan Liao
Keyword(s):  
Brittle Materials ◽  
Depth Of Cut ◽  
Specific Cutting Energy ◽  
Critical Depth ◽  
Cutting Depth ◽  
Crystal Silicon ◽  
Cutting Energy ◽  
Process Characteristics ◽  
Hard And Brittle Materials ◽  
Critical Depth Of Cut

This paper investigated the scribing process characteristics of the hard and brittle materials including single crystal silicon, STV glass, and sapphire substrate. Under various cutting angles, major process characteristics are examined including the groove geometry, specific cutting energy, and critical depth of cut at the onset of ductile-to-brittle cutting transition. As the cutting depth increases, groove geometry clearly reveals the ductile-to-brittle transition from the plastic deformation to a brittle fracture state. The material size effect in the ductile region as well as the transition in scribing behavior is well reflected by change in the specific cutting energy. Further, it is shown that the change of specific cutting energy as a function of the cutting depth can serve as a criterion for estimating the critical depth of cut. Such estimated critical depth of cut is confirmed by measurement from a 3D confocal microscope. The critical depths of cut for these hard materials are found to be between 0.1μm and 0.5μm depending on the materials and cutting angles.

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