Research Papers

Crystallographic Effects on Microscale Machining of Polycrystalline Brittle Materials

[+] Author and Article Information
Siva Venkatachalam

Corning Incorporated,
One Riverfront Plaza,
Corning, NY 14831

Xiaoping Li

Department of Mechanical Engineering,
National University of Singapore,
Singapore 119260, Singapore

Omar Fergani

Research Assistant
George W. Woodruff
School of Mechanical Engineering,
Georgia Institute of Technology,
Atlanta, GA 30332

Jiang Guo Yang

School of Mechanical Engineering,
Donghua University,
Shanghai 200051, China

Steven Y. Liang

George W. Woodruff
School of Mechanical Engineering,
Georgia Institute of Technology,
Atlanta, GA 30332

Contributed by the Manufacturing Engineering Division of ASME for publication in the JOURNAL OF Micro- AND Nano-Manufacturing. Manuscript received January 25, 2013; final manuscript received July 23, 2013; published online September 25, 2013. Assoc. Editor: Stefan Dimov.

J. Micro Nano-Manuf 1(4), 041001 (Sep 25, 2013) (9 pages) Paper No: JMNM-13-1010; doi: 10.1115/1.4025255 History: Received January 25, 2013; Revised July 23, 2013

This paper studies the effects of crystallography on the microscale machining characteristics of polycrystalline brittle materials on a quantitative basis. It is believed that during micromachining of brittle materials, plastic deformation can occur at the tool-workpiece interface due to the presence of high compressive stresses which leads to chip formation as opposed to crack propagation. The process parameters for such a machining process are comparable to the size of the grains, and hence crystallography assumes importance. The crystallographic effects include grain size, grain boundaries (GB), and crystallographic orientation (CO) for polycrystalline materials. The size of grains (crystals), whose distribution is analyzed as a log-normal curve, has an effect on the yield stress of a material as described by the Hall–Petch equation. The effects of grain boundary and orientation have been considered using the principles of dislocation theory. The microstructural anisotropy in a deformed polycrystalline material is influenced by geometrically necessary boundaries (GNB) and incidental dislocation boundaries (IDB). The dislocation theory takes both types of dislocations into account and relates the material flow stress to the dislocation density. The proposed analysis is compared with previously reported experimental data on polycrystalline germanium (p-Ge). This paper aims to provide a deeper physical insight into the microstructural aspects of polycrystalline brittle materials during precision microscale machining.

Copyright © 2013 by ASME
Your Session has timed out. Please sign back in to continue.



Grahic Jump Location
Fig. 1

Microstructure effects in machining [36]

Grahic Jump Location
Fig. 2

(Left) Sample grain structure of Alumina (Al2O3) and (right) lognormal distribution for grain size

Grahic Jump Location
Fig. 3

(Left) Machining model: a—depth of cut; h—undeformed chip thickness; f—feed; b—width of cut; and κ—cutting edge angle (reproduced from Ref. [10]) and (right) facing operation

Grahic Jump Location
Fig. 4

Experimental force data extracted from Ref. [10]

Grahic Jump Location
Fig. 5

(Left) Schematic of the grain map in polycrystalline germanium and (right) SEM picture of the grain map of polycrystalline germanium

Grahic Jump Location
Fig. 6

Comparison of predicted forces with corresponding experimental values

Grahic Jump Location
Fig. 7

Force comparison for grains A and B

Grahic Jump Location
Fig. 8

Main effects plot for cutting force (Fc)

Grahic Jump Location
Fig. 9

Main effects plot for thrust force (Ft)

Grahic Jump Location
Fig. 10

Main effects plot for shear angle (ϕ)




Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In