“1 gain . . . 
tess fe Atomic Force Microscopy Study of Ru-Al Eutectic 
of gh 
Wily N.Ilic, M.Goken*, M. Kempf *, K. Durst’, F.Soldera, N.Manent, F.Miicklich 
AAW e 
Tag I 
a ha Saarland University, Functional Materials Dept., Saarbriicken, Germany 
"ICON *) Saarland University, Materials Science Dept., Saarbrücken, Germany 
Abstract 
nn Young’s modulus of elasticity (E) and nanohardness (NH) of different microstructural features in 
RB hie eutectic Ru-Al alloy, were determined by nanoindentions using Atomic Force Microscope (AFM). 
a The eutectic alloy was investigated in as-cast and homogenized condition. The microstructure 
a! consisted of RuAl primary dendrites and fine lamellar and rod-like eutectic, which coarsened after 
deviaton of heat treatment. It is shown that local mechanical properties are affected by heat treatment and phase 
oi meth morphology. Surface profiles, clearly illustrate poor ability of -Ru phase to accommodate 
vlc ie deformation (formation of piled-up volume was observed), while intermetallic RuAl phase 
115 researCr. deformed readily. 
Ties regardless 
Introduction 
Ruthenium forms with aluminum a number of intermetallic compounds, but the equiatomic 
compound, RuAl, has attracted the greatest attention. Apart from its good oxidation and corrosion 
resistance, good thermal and electrical conductivity and high temperature strength, as compared to 
other B2 intermetallics, RuAl also has good room temperature ductility [1-4]. 
New 
Sl 40.0 nm 
1 Microscopy. hae 
idy of the 
a metall. 32 20.0 nm 
»rei-Technische 
sch‘ —— 40.0 nu 
u-Polyorystals a 
~ Fig. 1. Indentations in lamelar eutecticum (AFM). Fig. 2. Indentations in rod-like eutecticum (AFM). 
|-Pecher; 
agnetic Layers 
y of Materials 
pnof Thin 
hie. 37120000, 
cr0SCOPY a) = rar wo 2 we bi N c) | ne ap 500 
: Fig. 3. a-c. AFM general view of indentations in microstructure (b); 
details: pile up volume in a-Ru phase (a), RuAl phase (c). 
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