DIRD_01_Metallic_Glasses_for_Aerospace_Applications.pdf

14 December 2009 
ICOD: 1 December 2009 
DIA-08-0911-012 
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Defense 
Intelligence 
Reference 
Document 
Acquisition Threat Support 
Metallic Glasses: Status and 
Prospects for Aerospace 
Applications 
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Metallic Glasses: Status and Prospects for Aerospace 
Applications 
Prepared by: 
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Defense Intelligence Agency 
Author: 
l(b)(6) 
Administrative Note 
COPYRIGHT WARNING: Further dissemination of the photographs in this publication is not authorized. 
This product is one in a series of advanced technology reports produced in FY 2009 
under the Defense Intelligence Agency, l(b)(3):10 usc 424 
V\dvanced Aerospace 
Weapon System Applications (AAWSA) Program. Comments or questions pertaining to 
this document should be addressed…

UNCLASSIFIED --F@?-OFFtGEESr- OnE Contents SUIMIMALy waesene accesses Wa suenne sens snannecensneuancxeusecensensnansdanscanenssansnsease waeasenauansuanauansuenauanazans Vv Metallic GlaSS@S.......cscscnesescvenccususeneveseseseseveresssecceusesusecesevenssesuseeesesursvavevesuousevereressrye 1 Structure.....esssseees ween ea anne nnn renee ene ane nene nena menane namsnaneuenenenananeneuenasensmecauananenanenae 1 Processing PPS LES EL ELE SEL IAPS ESERIES EERE LETTE EEE ELL Ea IPRS PERS ELE LES ESSTTE TET EES 2 Glass-Forming AMOS. a. sesncccssenencsnersuecencsusensnancnueseuenesuaauensennaaeu…

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Current Challenges and Prospects for the Future ................................................. 20 
Alloy Design ...................................................................................................... 20 
Thermophysical Properties and Thermoplastic Processing ............................... 20 
Composites and the Quest for Ductility ............................................................ 21 
Summary and Recommendations ••••••••••••••••.••.••••••••••••••••••••••••••••••••••••••••••••••••••••• 22 
Figures 
1. Amorphous Versus Crys…

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Metallic Glasses: Status and Prospects for Aerospace 
Applications 
Summary 
Metallic glasses combine some of the advantageous mechanical properties of 
metals-strength, stiffness, and in some cases toughness-with the processing 
flexibillty usually associated with thermoplastic polymers. The absence of 
crystalline defects allows metallic glasses to be much stronger than 
conventional alloys but also means they have near-zero tensile ductility and 
poor fatigue resistance. In structural applications, therefore, metallic glasses 
are most likely to be us…

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The effect of alloy composition and structure on plastlc deformation. 
Microstructural design of composites for optimal toughness. 
• 
Development of processing techniques, including thermophysical 
processing of complex and/or nanoscale features as well as production of 
metallic glass foams. 
It is highly likely that continued work over the next 20-50 years will result in 
significant advances in all these areas, and that metallic glasses and metallic 
glass matrix composites will see increasing acceptance as structural materials. 
Whether or not…

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Metallic Glasses 
STRUCTURE 
The atomic-scale structure of most metals and alloys is crystalline; that is, the atoms 
are arranged in a highly ordered manner on a lattice that is periodic in three 
dimensions, as depicted in Figure l(a). In contrast to this crystalline structure, metallic 
glasses lack the long-range order of a lattice and are therefore said to be amorphous, 
as depicted in Figure l(b). Although the word "amorphous" implies a complete lack of 
structural order, in fact the atomic structure of metallic glasses is not truly random. 
C…

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glasses in the true sense of the word, rather than melting abruptly (as crystalline 
metals do), they soften and flow over a range of temperatures in a manner akin to 
common (oxide) glasses. This creates opportunities for tremendous flexibility in the 
processing of metallic glasses. 
PROCESSING 
Glass-Forming Alloys 
The key to making a metallic glass is to retain the disordered, liquid-like atomic scale 
structure during cooling from the melt. All materials have a tendency to crystallize upon 
cooling because the crystalline state is the most stable …