Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


NWHutchinson_PhD_Thesis.pdf (180.46 MB)

ETD Abstract Container

Abstract Header

Experimental input for the design of metallic glass/crystalline composites

Hutchinson, Nicholas W
http://rave.ohiolink.edu/etdc/view?acc_num=osu1385512484

Abstract Details

2013, Doctor of Philosophy, Ohio State University, Materials Science and Engineering.
Bulk metallic glasses often exhibit exceptional strength and large elastic strains, but the structural applications of bulk metallic glasses are limited by their extremely low tensile ductility. Below the glass transition temperature of the alloy, plastic deformation occurs primarily in narrow shear bands, which propagate unimpeded through the monolithic glass structure, resulting in catastrophic failure under tensile loading. A number of studies have added crystalline reinforcements to the glassy matrix in an effort to block shear band propagation and increase ductility. The reinforcements in these bulk metallic glass matrix composites (BMGMC’s) can be added as ex situ particles or fibers infiltrated by the glass- forming liquid, or can be formed in situ, either via devitrification of the glass during post-processing or as a second phase that precipitates from the melt during solidification . The size, distribution, and mechanical properties of the reinforcement phase have significant impact on the ductility of the composite. However, surprisingly little quantitative microstructural information is available for BMGMC’s, particularly those formed by precipitation from the melt. In this work, we examine two in situ BMGMC’s in which a ductile crystalline phase precipitates during solidification of the melt, resulting in a complex dendritic structure embedded in a continuous glass matrix. A 3D serial sectioning process was used to image the microstructure at regular intervals by removing slices of material using a dual beam focused ion – scanning electron microscope (FIB). Due to the complex nature of the microstructure, measurements of key features were conducted using a 3D measurement method that was developed for this purpose. Experiments were also conducted to provide experimental input for the development and tuning of finite element models. Changes in the elastic modulus of the composite were evaluated over a range of stresses that encompassed the yield point of the composite. An interesting increase in the modulus was observed prior to yielding. The work is concluded with a study of the accumulation of strain within the composite microstructure during tensile loading. The strain was determined and evaluated by a digital image correlation method.
Katharine Flores, PhD (Advisor)
Wolfgan Windl, PhD (Advisor)
Glenn Daehn, PhD (Committee Member)
Stephen Niezgoda, PhD (Committee Member)
214 p.
Materials Science
metallic glass; composite; microstructure; digital image correlation

Recommended Citations

Citations

  • Hutchinson, N. W. (2013). Experimental input for the design of metallic glass/crystalline composites [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1385512484

    APA Style (7th edition)

  • Hutchinson, Nicholas. Experimental input for the design of metallic glass/crystalline composites. 2013. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1385512484.

    MLA Style (8th edition)

  • Hutchinson, Nicholas. "Experimental input for the design of metallic glass/crystalline composites." Doctoral dissertation, Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1385512484

    Chicago Manual of Style (17th edition)

osu1385512484
212
© 2013, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.