Thermal and Structural Deformations During Diamond Turning of Rotationally Symmetric Structured Surfaces

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Stefan Rakuff ◽  
Paul Beaudet
Keyword(s):  
Cutting Tool ◽  
Diamond Turning ◽  
Machining Process ◽  
Diamond Cutting ◽  
Structured Surfaces ◽  
Optical Films ◽  
Single Crystal Diamond ◽  
Structural Loop ◽  
Diamond Cutting Tool ◽  
Aerostatic Spindle

Diamond turning of microstructures on the surface of large cylindrical workpieces has become important with advances made in roll-to-roll manufacturing processes of optical films, drag reduction films, microfluidic devices, and organic electronic components. Micromachined cylindrical workpieces are used as production masters in various printing, embossing, and coating processes. The microstructures machined in this study were 18μm in height and had a pitch of 35μm. These dimensions required control of the location of the single crystal diamond cutting tool that was used for machining to submicrometer levels. The significant error sources identified in the machining process were thermal effects and deflections of the structural loop of the diamond turning machine (DTM) that led to registration errors of the cutting tool between consecutive passes. Environmental temperature variation errors (ETVEs) were measured and modeled as a function of long-term ambient temperature fluctuations. Also studied was the mechanical compliance of the structural loop of the DTM. The height adjustable tool stack and aerostatic spindle were identified as the most compliant components. The cutting forces for radius and V-shaped diamond cutting tools at various depths of cut were measured using the known compliance of the aerostatic bearing to predict workpiece deflections.

Microtexture Generation Using Controlled Chatter Machining in Ultraprecision Diamond Turning

2015 ◽  
Vol 3 (2) ◽  
Author(s):  
Syed Adnan Ahmed ◽  
Jeong Hoon Ko ◽  
Sathyan Subbiah ◽  
Swee Hock Yeo
Keyword(s):  
Cutting Tool ◽  
Cutting Speed ◽  
Diamond Turning ◽  
Diamond Cutting ◽  
Machined Surface ◽  
Excited Vibration ◽  
Mass And Heat Transfer ◽  
Tool Shank ◽  
Diamond Cutting Tool

This paper describes a new method of microtexture generation in precision machining through self-excited vibrations of a diamond cutting tool. Conventionally, a cutting tool vibration or chatter is detrimental to the quality of the machined surface. In this study, an attempt is made to use the cutting tool's self-excited vibration during a cutting beneficially to generate microtextures. This approach is named as “controlled chatter machining (CCM).” Modal analysis is first performed to study the dynamic behavior of the cutting tool. Turning processes are then conducted by varying the tool holder length as a means to control vibration. The experimental results indicate that the self-excited diamond cutting tool can generate microtextures of various shapes, which depend on the cutting tool shank, cutting speed, feed, and cutting depth. The potential application of this proposed technique is to create microtextures in microchannels and microcavities to be used in mass and heat transfer applications.

Single Point Diamond Turning of Silicon by Using Micro-Laser Assisted Machining Technique

2014 ◽  
Author(s):  
Hossein Mohammadi ◽  
H. Bogac Poyraz ◽  
Deepak Ravindra ◽  
John A. Patten
Keyword(s):  
Fiber Laser ◽  
Cutting Tool ◽  
Single Point ◽  
Diamond Turning ◽  
Depth Of Cut ◽  
Beam Diameter ◽  
Diamond Cutting ◽  
Laser Assisted Machining ◽  
Diamond Cutting Tool ◽  
Si Wafer

In this study, single point diamond turning (SPDT) is coupled with the micro-laser assisted machining (μ-LAM) technique. The μ-LAM system is used to preferentially heat and thermally soften the work piece material in contact with a diamond cutting tool. In μ-LAM the laser and cutting tool are integrated into a single package, i.e. the laser energy is delivered by a single mode fiber laser to and through a diamond cutting tool. This hybrid method can potentially increase the critical depth of cut (DoC), i.e., a larger ductile-to-brittle transition (DBT) depth, in ductile regime machining, resulting in a higher material removal rate (MRR). An IR continuous wave (CW) fiber laser, wavelength of 1064nm and max power of 100W with a beam diameter of 10μm, is used in this investigation. In the current study SPDT tests were employed on single crystal silicon (Si) wafer which is very brittle and hard to machine by conventional methods. Different outputs such as surface roughness and depth of cut for different set of experiments were analyzed. Results show that an unpolished surface of a Si wafer can be machined in one pass to get a very good surface finish. The Ra was brought down from 1.2μm to 275nm only in one pass which is a very promising result for machining the Si wafer.

Controllability Study of Single-Crystal Diamond Cutting Tool Focus Ion Beam Milling with Different Beam Current and Tilting Angle

2016 ◽  
Vol 1136 ◽  
pp. 430-434 ◽  
Author(s):  
Seung Yub Baek ◽  
Woong Kirl Choi ◽  
Young Jae Choi ◽  
Eun Sang Lee
Keyword(s):  
Cutting Tool ◽  
Ion Beam ◽  
Beam Current ◽  
Diamond Cutting ◽  
Tilting Angle ◽  
Tool Edge ◽  
Single Crystal Diamond ◽  
Processing Procedure ◽  
Edge Sharpness ◽  
Diamond Cutting Tool

Micro/nanoscale diamond cutting tools used in ultra-precision machining can be fabricated by precision grinding, but it is hard to fabricate a tool with a nanometric cutting edge and complex configurations. High-precision geometry accuracy and special shapes for microcutting tools with sharp edges can be achieved by focused ion beam (FIB) milling. However, in the FIB milling process, the surface properties of the substrate (such as a diamond substrate) are affected by the amorphous damage layer caused by the FIB gallium ion collision and implantation and these influence the diamond cutting tool edge sharpness and increase the processing procedure. In this study, to reduce the diamond cutting tool edge sharpness and processing procedure, FIB milling beam current and tilting angle characteristics of single-crystal diamond were investigated, along with method for decreasing the FIB-induced damage on diamond tools by platinum (Pt) coating on the diamond substrate. Experimental results revealed that optimize beam current, tilting angle and platinum (Pt) coating could lead to relatively few processing procedure and sharp cutting tool edge. The obtained results are an endeavor to enhance the controllability of the diamond cutting tool FIB milling.

scholarly journals Graphitization Behavior of Single Crystal Diamond for the Application in Nano-Metric Cutting

2018 ◽  
Vol 14 (5) ◽  
pp. 377-383 ◽  
Author(s):  
Qingshun Bai ◽  
Zhiguo Wang ◽  
Yongbo Guo ◽  
Jiaxuan Chen ◽  
Yuanjiang Shang
Keyword(s):  
Molecular Dynamics ◽  
Single Crystal ◽  
Cutting Tool ◽  
Diamond Tool ◽  
Diamond Crystal ◽  
Dynamics Simulation ◽  
Diamond Cutting ◽  
Single Crystal Diamond ◽  
Ring Method ◽  
Diamond Cutting Tool

Background: Graphitization behavior of diamond has received an increasing interest in nanoscale machining of some hard and brittle materials. Diamond has always been an important and excellent tool material in cutting area. However, the graphitization of the diamond tool is inevitable when it was used in special conditions. It is indicated that the graphitization of diamond crystal has great influence on the wear resistance of diamond cutting tool. The graphitization behavior needs to be investigated extensively in nanoscale with an atomic view. Molecular dynamics simulation provides a useful tool for understanding of the graphitization mechanism of diamond. The investigation on graphitization behavior of single crystal diamond can also provide a useful reference for the application of diamond cutting tool. Materials and Methods: In this paper, a molecular dynamics (MD) diamond crystal model is built to examine the graphitization behavior of diamond under various conditions. The sixfold ring method was employed to identify the structural characteristics of graphite and diamond. The effects of temperature and crystal orientation on the graphitization of diamond have been revealed. Considering the effect of temperature, the anisotropy of diamond graphitization against various crystal planes is presented and discussed carefully. The nano-metric cutting model of diamond tool evaluated by the sixfold ring method also proves the graphitization mechanisms in atomic view. Results: Results indicate that the sixfold ring method is a reliable method to evaluate the graphitization behavior of diamond crystal. There exists a critical temperature of the graphitization of diamond. The results also show that {111} plane is more easy to get graphitization as compared with other crystal planes. However, {100} plane of diamond model presents the highest antigraphitization property. Conclusion: The obtained results have provided the in-depth understanding on the wear of diamond tool in nano-metric machining and underpin the development of diamond cutting tool.

scholarly journals The wear of single-crystal diamond cutting tool.

1989 ◽  
Vol 55 (2) ◽  
pp. 347-353
Author(s):  
Masanori Yoshikawa ◽  
Kunihiko Kikuchi ◽  
Tadao Tsukada ◽  
Kazuyuki Sasajima
Keyword(s):  
Single Crystal ◽  
Cutting Tool ◽  
Diamond Cutting ◽  
Single Crystal Diamond ◽  
Diamond Cutting Tool

Temperature and Stress Analysis in Micro-Cutting of Ti-6Al-4V and Al7050-T6

2010 ◽  
Vol 97-101 ◽  
pp. 3005-3009
Author(s):  
Dong Lu ◽  
Guo Hua Qin ◽  
Cong Kang Wang ◽  
Yi Ming Rong
Keyword(s):  
Finite Element Method ◽  
Cutting Tool ◽  
Thrust Force ◽  
Cutting Temperature ◽  
Rake Angle ◽  
The Other ◽  
Machining Process ◽  
Diamond Cutting ◽  
Workpiece Material ◽  
Diamond Cutting Tool

A finite element method (FEM) for predicting the temperature and stress distribution is presented. Two workpiece materials were carried out, one is Al7050-T6 the other is Ti-6Al-4V. The flow stress of workpiece material is taken as a function of strain, strain rate and temperature in order to reflect realistic behavior in machining process. Diamond cutting tool with rake angle 50, clearance angle 100, and cutting edge radius 1 is used. From simulation, cutting force, thrust force, and distribution of cutting temperature and stress are obtained.

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