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.

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.

Experimental Investigation of the Machinability of Single Crystal Silicon in Laser-Assisted Diamond Cutting

2020 ◽  
Author(s):  
Jinyang Ke ◽  
Xiao Chen ◽  
Jianguo Zhang ◽  
Changlin Liu ◽  
Guoqing Xu ◽  
...  
Keyword(s):  
Single Crystal ◽  
Surface Quality ◽  
Laser Power ◽  
Single Crystal Silicon ◽  
Depth Of Cut ◽  
Maximum Height ◽  
Critical Depth ◽  
Diamond Cutting ◽  
Crystal Silicon ◽  
Critical Depth Of Cut

Abstract Laser-assisted diamond cutting is a promising process for machining hard and brittle materials. A deep knowledge of material removal mechanism and attainable surface integrity are crucial to the development of this new technique. This paper focuses on the application of laser-assisted diamond cutting to single crystal silicon to investigate key characteristics of this process. The influence of laser power on the ductile machinability of single crystal silicon, in terms of the critical depth of cut for ductile-brittle transition in laser-assisted diamond cutting, is investigated quantitatively using a plunge-cut method. The experimental results reveal that this process can enhance the silicon’s ductility and machinability. The critical depth of cut has been increased by up to 330% with laser assistance, and its degree generally increases with the increase of laser power. The cross-sectional transmission electron microscope observation results indicate that laser-assisted diamond cutting is able to realize the subsurface damage free processing of single crystal silicon. In order to verify the ability of the laser-assisted diamond cutting to improve the surface quality, the face turning tests are also carried out. A significant improvement of surface quality has been obtained by laser-assisted diamond cutting: Sz (maximum height) has been reduced by 85% and Sa (arithmetical mean height) has been reduced by 45%.

scholarly journals Effect of Thermal Softening on Anisotropy and Ductile Mode Cutting of Sapphire Using Micro-Laser Assisted Machining

2017 ◽  
Vol 5 (1) ◽  
Author(s):  
Hossein Mohammadi ◽  
John A. Patten
Keyword(s):  
Removal Rate ◽  
Brittle Materials ◽  
Single Crystal Silicon ◽  
Thermal Softening ◽  
Depth Of Cut ◽  
Crystal Silicon ◽  
Ductile Mode ◽  
Hard And Brittle Materials ◽  
Fracture Damage ◽  
Diamond Cutting Tool

Ceramics and semiconductors have many applications in optics, micro-electro-mechanical systems, and electronic industries due to their desirable properties. In most of these applications, these materials should have a smooth surface without any surface and subsurface damages. Avoiding these damages yet achieving high material removal rate in the machining of them is very challenging as they are extremely hard and brittle. Materials such as single crystal silicon and sapphire have a crystal orientation or anisotropy effect. Because of this characteristic, their mechanical properties vary significantly by orientation that makes their machining even more difficult. In previous works, it has been shown that it is possible to machine brittle materials in ductile mode. In the present study, scratch tests were accomplished on the monocrystal sapphire in four different perpendicular directions. A laser is transmitted to a diamond cutting tool to heat and soften the material to either enhance the ductility, resulting in a deeper cut, or reducing brittleness leading to decreased fracture damage. Results such as depth of cut and also nature of cut (ductile or brittle) for different directions, laser powers, and cutting loads are compared. Also, influence of thermal softening on ductile response and its correlation to the anisotropy properties of sapphire is investigated. The effect of thermal softening on cuts is studied by analyzing the image of cuts and verifying the depth of cuts which were made by using varying thrust load and laser power. Macroscopic plastic deformation (chips and surface) occurring under high contract pressures and high temperatures is presented.

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.

Micro-Machinability Studies of Single Crystal Silicon Using Diamond End-Mill

2016 ◽  
Author(s):  
Zi Jie Choong ◽  
Dehong Huo ◽  
Patrick Degenaar ◽  
Anthony O’Neill
Keyword(s):  
Size Effect ◽  
Single Crystal Silicon ◽  
Micro Milling ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Specific Cutting Energy ◽  
Crystal Silicon ◽  
Edge Chipping ◽  
Cutting Energy ◽  
Machining Conditions

This paper presents the research on the machinability studies in micro-milling of (001) silicon wafer. Excessive generation of undesirable surface and subsurface damages such as surface edge chipping often occurs when machined at depth of cut of several hundreds of microns. Ideal machining strategy to reduce the generation of edge chipping is required. Investigations on the effect of machining conditions on the cutting performances and size effect on the specific cutting energy in silicon micro-milling were conducted. These investigations provide understandings on the behavior of cutting mechanism during machining and helps to identify suitable machining parameters for fracture free machining using diamond end mills. Full slot milling were performed along <100> and <110> directions on a (001) surface wafer under various machining conditions. Results show that machined surfaces along <100> were of better quality than those along <110> and is in agreement with previous studies. Furthermore, good machining quality was achieved when machined at depth of cut of 10 μm or feed per tooth of 0.075 μm/tooth, regardless of the machining conditions. In addition, investigation for the size effect on specific cutting energy also shows that brittle mode machining begins when feed per tooth increases beyond 0.4 μm/tooth.

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