Skip to page content
USDA Forest Service
  
Treesearch

Research & Development Treesearch

 
Treesearch Home
About Treesearch
Contact Us
Research & Development
Forest Products Lab
International Institute of Tropical Forestry
Northern
Pacific Northwest
Pacific Southwest
Rocky Mountain
Southern
Help
 

GeoTreesearch


Science.gov - We Participate


USA.gov  Government Made Easy


Global Forest Information Service

US Forest Service
P.O. Box 96090
Washington, D.C.
20090-6090

(202) 205-8333

You are here: Home / Search / Publication Information
Bookmark and Share

Publication Information

(103 KB)

Title: Shear transformation zone activation during deformation in bulk metallic glasses characterized using a new indentation creep technique

Author: Puthoff, J.B.; Cao, H.B.; Jakes, Joseph E.; Voyles, P.M.; Stone, D.S.

Date: 2009

Source: Local structure and dynamics in amorphous systems [electronic resource]. Materials Research Society symposium proceedings ; v. 1152. Warrendale, Pa. : Materials Research Society, [2009] : [6] pages. ISBN: 9781605111247: 1605111244.

Publication Series: Not categorized

Description: We have developed a novel type of nanoindentation creep experiment, called broadband nanoindentation creep (BNC), and used it to characterize the thermal activation of shear transformation zones (STZs) in three BMGs in the Zr-Cu-Al system. Using BNC, material hardness can be determined across a wide range of strain rates (10–4 to 10 s–1) in a single experiment at room temperature. This data can be used to characterize the kinetics of deformation, including the free energy function (ΔG) for thermally-activated deformation. We have found that the activation energy agrees with the theory of Johnson and Samwer, in which ΔG ∝ [(τc – τ)/τc]3/2, where τ is the flow stress and τc is the flow stress at 0K. In the context of their model, we estimate that the volume of an STZ is ~ 100-300 atomic volumes and the activation energies for low-stress deformation are 5-10 eV. From these measurements, it is possible to reproduce the temperature dependence of the flow stress.

Keywords: Metallic glasses, materials, creep, testing, strains, stresses, deformations, nanotechnology, nanostructured materials, measurement, zirconium, copper, aluminum, hardness, shear, temperature, elasticity, broadband nanoindentation creep, BNC, creep, kinetics, nanoindentation

Publication Notes:

  • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
  • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.

XML: View XML

Citation:


Puthoff, J.B.; Cao, H.B.; Jakes, Joseph E.; Voyles, P.M.; Stone, D.S. 2009. Shear transformation zone activation during deformation in bulk metallic glasses characterized using a new indentation creep technique. Local structure and dynamics in amorphous systems [electronic resource]. Materials Research Society symposium proceedings ; v. 1152. Warrendale, Pa. : Materials Research Society, [2009] :[6] pages. ISBN: 9781605111247:1605111244

 


 [ Get Acrobat ]  Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility

USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.