Nanoindentation and orientation imaging: Probing small volumes and thin films for mechanical properties

Bahr, David F.; Nibur, Kevin A.; Morasch, K. R.

doi:10.1007/s11664-002-0174-8

Cited by 10 publications

(2 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It was shown in earlier work at Washington State University [21] that AFM can be used in conjunction with OIM to identify specific slip planes responsible for any particular slip step visible on a material's surface around an indentation . Similar techniques have been used to identify slip steps around STM tip indentations in gold [22], within the cavity left by spherical indentations in MnZn ferrite [23], and around Berkovich indentations in MgO and LiF [24][25][26].…”

Section: Analysis Of Slip Steps Around Indentationmentioning

confidence: 99%

Development of experimental verification techniques for non-linear deformation and fracture on the nanometer scale.

Moody¹,

Bahr²

2005

View full text Add to dashboard Cite

This work covers three distinct aspects of deformation and fracture during indentations. In particular, we develop an approach to verification of nanoindentation induced film fracture in hard film / soft substrate systems ; we examine the ability to perform these experiments in harsh environments; we investigate the methods by which the resulting deformation from indentation can be quantified and correlated to computational simulations, and we examine the onset of plasticity during indentation testing.First, nanoindentation was utilized to induce fracture of brittle thin oxide films on compliant substrates . During the indentation, a load is applied and the penetration depth is continuously measured . A sudden discontinuity, indicative of film fracture, was observed upon the loading portion of the load-depth curve . The mechanical properties of thermally grown oxide films on various substrates were calculated using two different numerical methods . The first method utilized a plate bending approach by modeling the thin film as an axisymmetric circular plate on a compliant foundation . The second method measured the applied energy for fracture. The crack extension force and applied stress intensity at fracture was then determined from the energy measurements.Secondly, slip steps form on the free surface around indentations in most crystalline materials when dislocations reach the free surface . Analysis of these slip steps provides information about the deformation taking place in the material . Techniques have now been developed to allow for accurate and consistent measurement of slip steps and the effects of crystal orientation and tip geometry are characterized . These techniques will be described and compared to results from dislocation dynamics simulations.iii Finally, the stress required to cause fracture of passive films on stainless steels was studied using nanoindentation under in situ and ex situ conditions . For films formed at a passive potential, the alloy chemistry dominated the film strength . Increasing the electrolyte salt concentration from O .O1M NaCl to O .1M NaCl and changing the substrate on which the film was grown from 904L to 304 stainless steels reduced the applied tensile stress for fracture from 1 .74GPa to 1 .63GPa and from 1 .76GPa to 1 .63GPa, respectively . Trends in film strength as a function of environment are the same between in situ and ex situ testing, suggesting the two tests are both feasible methods of analyzing environmental effects on film strength.iv CONTENTS

show abstract

Section: Analysis Of Slip Steps Around Indentationmentioning

confidence: 99%

Development of experimental verification techniques for non-linear deformation and fracture on the nanometer scale.

Moody¹,

Bahr²

2005

View full text Add to dashboard Cite

show abstract

“…24 papers and presentations made possible by REU student's work, as examples [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. This accounts for about 45%, which is significantly higher than the approximately 20% of engineering undergraduates in the country.…”

Section: Success Metricsmentioning

confidence: 99%

Incorporating Diverse Majors and Backgrounds in Materials Science Research Experience for Undergraduates (REU) Sites

Bahr

Norton

2004

MRS Proc.

View full text Add to dashboard Cite

A summer Research Experience for Undergraduate (REU) site program has been operating at Washington State University for the past five summers. Over this time we have experimented with several modes of organized summer research methods, including students working in individual projects as well as students working in teams. We have balanced the academic standing of the students (freshmen to seniors), as well providing a diverse demographic background. The results of these past five summers will be presented, as well as recommendations for which methods have been the most successful in terms of generating publications and presentations from the students as well as the likelihood of students entering graduate school.

show abstract

Localized Deformation Around Indentations and the Effects of Hydrogen on Dislocation Cross-Slip

Nibur¹,

Bahr²

2013

Materials Lifetime Science &Amp; Engineering

View full text Add to dashboard Cite

Nanoindentation and orientation imaging: Probing small volumes and thin films for mechanical properties

Cited by 10 publications

References 16 publications

Development of experimental verification techniques for non-linear deformation and fracture on the nanometer scale.

Development of experimental verification techniques for non-linear deformation and fracture on the nanometer scale.

Incorporating Diverse Majors and Backgrounds in Materials Science Research Experience for Undergraduates (REU) Sites

Localized Deformation Around Indentations and the Effects of Hydrogen on Dislocation Cross-Slip

Contact Info

Product

Resources

About