0
Special Section: Micromanufacturing

Effects of Crystallographic Anistropy on Orthogonal Micromachining of Single-Crystal Aluminum

[+] Author and Article Information
Benjamin L. Lawson, Nithyanand Kota

Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213

O. Burak Ozdoganlar1

Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213ozdoganlar@cmu.edu

1

Corresponding author.

J. Manuf. Sci. Eng 130(3), 031116 (Jun 03, 2008) (11 pages) doi:10.1115/1.2917268 History: Received May 30, 2006; Revised December 17, 2007; Published June 03, 2008

Anisotropy of workpiece crystals has a significant effect in micromachining since the uncut chip thickness values used in micromachining are commensurate with characteristic dimensions of crystals in crystalline materials. This paper presents an experimental investigation on orthogonal micromachining of single-crystal aluminum at different crystallographic orientations for varying uncut chip thicknesses and cutting speeds using a diamond tool. Micromachining forces, specific energies, effective coefficient of friction, shear angles, shear stresses, and chip morphology were examined for six crystallographic orientations at uncut chip thicknesses ranging from 5μmto20μm and cutting speeds ranging from 5mmsto15mms. Three distinct types of forces were observed, including steady (Type-I), bistable (Type-II), and fluctuating (Type-III) force signatures. The forces were seen to vary by as much as threefold with crystallographic orientation. Although the effect of cutting speed was small, the uncut chip thickness was seen to have a significant orientation-dependent effect on average forces. Chip morphology, analyzed under scanning electron microscopy, showed shear-front lamella, the periodicity of which was seen to vary with crystallographic orientations and uncut chip thicknesses.

FIGURES IN THIS ARTICLE
<>
Copyright © 2008 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

(a) Diagram of the single-crystal cutting process and (b) projection of the crystallographic orientations onto the standard stereographic triangle

Grahic Jump Location
Figure 2

Diagram of the cutting planes and cutting directions used during the experimentation

Grahic Jump Location
Figure 3

The experimental testbed

Grahic Jump Location
Figure 4

Cutting (C), thrust (T), and lateral (L) forces for (a) (12 5 0) facet for 5mm∕s and 20μm, (b) (6 7 0) facet with 10mm∕s and 20μm, (c) (3 2 0) facet with 5mm∕s and 5μm, and (d) (2 7 0) facet with 5mm∕s and 5μm

Grahic Jump Location
Figure 5

Forces from three repetitions on (2 7 0) facet for 5mm∕s speed and 5μm prescribed uncut chip thickness

Grahic Jump Location
Figure 6

The specific cutting energies for (a) 5mm∕s, (b) 10mm∕s, and (c) 15mm∕s; and the specific thrust energies for (d) 5mm∕s, (e) 10mm∕s, and (f) 15mm∕s

Grahic Jump Location
Figure 7

The effective coefficient of friction for (a) 5mm∕s, (b) 10mm∕s, and (c) 15mm∕s

Grahic Jump Location
Figure 8

Shear angles for (a) 5mm∕s, (b) 10mm∕s, and (c) 15mm∕s.

Grahic Jump Location
Figure 9

Shear stresses for (a) 5mm∕s, (b) 10mm∕s, and (c) 15mm∕s

Grahic Jump Location
Figure 10

SEM images of chips from the (2 7 0) orientation illustrating the perspectives and magnifications used in analysis

Grahic Jump Location
Figure 11

SEM image of the face of the chips produced on the (2 7 0) orientation

Grahic Jump Location
Figure 12

Shear-front lamella at 20μm prescribed uncut chip thickness and 15mm∕s speed for (a) (2 9 0), (b) (2 7 0), (c) (4 11 0), (d) (12 5 0), (e) (3 2 0), and (f) (6 7 0) crystallographic orientations

Grahic Jump Location
Figure 13

450× magnification SEM image illustrating the difference between the apparent thickness of the lamella from the face and the profile views for the (2 9 0) orientation at 10mm∕s and 20μm prescribed uncut chip thickness

Grahic Jump Location
Figure 14

SEM image comparing lamellae and chip thicknesses before (top) and after (bottom) the transition for the bistable case of the (6 7 0) orientation with v=10mm∕s and hcp=20μm

Tables

Errata

Discussions

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