skip to main content

Attention:

The NSF Public Access Repository (PAR) system and access will be unavailable from 11:00 PM ET on Friday, December 13 until 2:00 AM ET on Saturday, December 14 due to maintenance. We apologize for the inconvenience.


Title: Ultra-Precision Machining: Cutting With Diamond Tools
Abstract This article is written as a tribute to Professor Frederick Fongsun Ling 1927–2014. Single-point diamond machining, a subset of a broader class of processes characterized as ultraprecision machining, is used for the creation of surfaces and components with nanometer scale surface roughnesses, and submicrometer scale geometrical form accuracies. Its initial development centered mainly on the machining of optics for energy and defense related needs. Today, diamond machining has broad applications that include the manufacture of precision freeform optics for defense and commercial applications, the structuring of surfaces for functional performance, and the creation of molds used for the replication of a broad range of components in plastic or glass. The present work focuses on a brief review of the technology. First addressed is the state of current understanding of the mechanics that govern the process including the resulting forces, energies and the size effect, forces when cutting single crystals, and resulting cutting temperatures. Efforts to model the process are then described. The workpiece material response when cutting ductile and brittle materials is also included. Then the present state of the art in machine tools, diamond tools and tool development, various cutting configurations used, and some examples of diamond machined surfaces and components are presented. A discussion on the measurement of surface topography, geometrical form, and subsurface damage of diamond machined surfaces is also included.  more » « less
Award ID(s):
1727244
PAR ID:
10296424
Author(s) / Creator(s):
; ;
Date Published:
Journal Name:
Journal of Manufacturing Science and Engineering
Volume:
142
Issue:
11
ISSN:
1087-1357
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Single-crystal calcium fluorite (CaF2) is widely used for transmissive optics in ultraviolet and vacuum ultraviolet (UV and VUV) wavelength applications because of its exceptional transmission performance. Generally, products using CaF2 are manufactured through finishing processes such as chemo-mechanical polishing (CMP), magnetorheological finishing (MRF) or ion-beam figuring (IBF) after performing precision cutting and grinding processes for profiling. However, CaF2 is known as a brittle material with high anisotropy, and subsurface damage is induced by each cutting process. But, the effects of surface integrity on the optical and functional performance of precision machined CaF2 has not been reported yet. In this research, a newly developed multiaxial adjustment system that can precisely align specimens is used in single-axis orthogonal cutting experiments with zero degree and negative rake angle diamond radius tools to prevent pre-machining and thus pre-damaging of single-crystal CaF2 specimens. Cutting forces evaluation via piezoelectric dynamometer acquisition as well as surface analysis by atomic force microscopy and white light microscopy has been performed. Finally, smooth surfaces due to ductile material removal mechanisms could be determined on all machined specimen surfaces. 
    more » « less
  2. Single crystal calcium fluoride (CaF2) is widely used for transmissive optics in the ultraviolet and vacuum ultraviolet (UV and VUV) spectral regions because of its high optical transmission. Optical components made of CaF2 are usually manufactured by precision machining to generate high quality surfaces with low surface roughness. However, the influence of the clamping technique on the resulting surface roughness of diamond machined CaF2 has not been reported. In this research, two clamping techniques, vacuum clamping and gluing with wax, are used in off-axis diamond turning experiments with zero degree and negative rake angle diamond tools. Surface characterization by white light interferometry and atomic force microscopy show surfaces with low surface roughness. Furthermore, a significant influence of the clamping technique on the generated surface topography is observed. 
    more » « less
  3. Abstract Single crystal Ge is a semiconductor that has broad applications, especially in manipulation of infrared light. Diamond machining enables the efficient production of surfaces with tolerances required by the optical industry. During machining of anisotropic single crystals, the cutting direction with respect to the in-plane lattice orientation plays a fundamental role in the final quality of the surface and subsurface. In this study, on-axis face turning experiments were performed on an undoped (111)Ge wafer to investigate the effects of crystal anisotropy and feedrate on the surface and subsurface conditions. Atomic force microscopy and scanning white light interferometry were used to characterize the presence of brittle fracture on the machined surfaces and to evaluate the resultant surface roughness. Raman spectroscopy was performed to evaluate the residual stresses and lattice disorder induced by the tool during machining. Nanoindentation with Berkovich and cube corner indenter tips was performed to evaluate elastic modulus, hardness, and fracture toughness of the machined surfaces and to study their variations with feedrate and cutting direction. Post-indentation studies of selected indentations were also performed to characterize the corresponding quasi-plasticity mechanisms. It was found that an increase of feedrate produced a rotation of the resultant force imparted by the tool indicating a shift from indentation-dominant to cutting-dominant behavior. Fracture increased with the feedrate and showed a higher propensity when the cutting direction belonged to the <112¯> family. 
    more » « less
  4. This paper describes the development and performance evaluation of a manual multi-axes workpiece adjustment system for ultra-precision diamond machining that is capable of holding a CaF2 specimen with high positioning accuracy without pre-machining. Experiments revealed that the specimen alignment system developed in this study has sub-micrometer adjustment resolution and demonstrates a stiffness that can withstand diamond cutting forces. Applying this system to diamond cutting of CaF2 produced an error of nominal cut thickness of at most 10 nm on both ends of the 10.5 mm cutting length and achieved a defect-free finished surface. 
    more » « less
  5. null (Ed.)
    Production-volume and cost requirements currently limit machine tool manufacturers’ ability to produce application-specific tooling with traditional methods, motivating the development of innovative manufacturing technologies. To this end, we detail a manufacturing framework for the design and production of application-specific cutting tools based on industry standard tungsten carbide-cobalt (WC-Co)-based “carbide” cutting materials using additive manufacturing (AM). Herein, novel diamond-reinforced carbide structures were designed and manufactured via AM and subsequently tested in comparison to current commercial products that are traditionally-processed. The resulting diamond-reinforced composites were free from large scale cracking and maintained microstructures with multiple reinforcing phases. Diamond incorporation had a remarkable effect on the processing, microstructure, and machining performance of the WC-Co based material in comparison to a commercial carbide cutting tool of similar composition as well as the base WC-Co matrix. Detailed microstructure and phase analysis, as well as machining experiments, demonstrate the ability to exploit laser-based directed energy deposition (DED)-based AM to create multifunctional cutting tools that can be designed to meet ever-increasing manufacturing demands across many industries. 
    more » « less