154 Prakt. Met. Sonderband 38 (2006) 
solidification conditions. However, the evolution of the solidification microstructure is mostly 
determined by the nucleation and growth kinetics of the solid phase [3]. 
Interpretation of rapidly solidified, metastable microstructures demands good knowledge of 
the rapid solidification technique, the solidification conditions, equilibrium behaviour of the 
alloy, inclination of the alloy to deviate from the equilibrium and finally correct metallographic A 
preparation of the sample. However, it is not easy to fulfil the last requirement in the case of usil 
rapidly solidified samples. Namely, in all cases, the obtained products are very small in ma 
dimension and it is difficult to carry out the authentic metallographic preparation and zirc 
consequently the quality microstructural examination. Moreover, the strain energy which is whi 
entered during grinding and polishing into the sample can cause the transformation of Me 
metastable materials constituents. Furthermore, because of small dimension of the samples of 
(thin ribbons, powders) there is the problem to retain good edge quality. The additional abc 
problem presents the retention of the second phase particles or fine precipitates. Finally, 0.8 
because of very fine microstructures with grains of submicron size and high portion of anc 
boundary region the samples often contain artefacts in the microstructure. Therefore, a The 
traditional metallographic preparation of rapidly solidified samples for optical and scanning by 
electron microscopy, consisting of hot or cold mounting, grinding, polishing and etching, sys 
might not be sufficient to interpret correctly the resulting microstructure. Sys 
Up to date different preparation techniques have been applied to overcome the above anc 
mentioned problems. One of them is the FIB technology. ele 
A FIB system is a tool that has a high degree of analogy with focused electron beam system cut 
such as a scanning electron microscope (SEM). In both instruments a charged particle 
beam is rastered across a solid surface thereby producing an image at high resolution of the 
surface being surveyed [4]. However, in the SEM the charged particles are electrons drawn ä 
from a single crystal and in the FIB they are gallium ions drawn from a liquid metal ion 
source. In both cases, the charged particles - surface interaction produces secondary The 
electrons which are used to create the image seen by the viewer, and just like backscattered allc 
electrons can be used to provide different material contrast in the SEM, backscattered affe 
gallium ions can be used to produce comparable imagery in the FIB. The most fundamental me 
difference between SEM and FIB is the mass difference between the charged species MO 
involved in the interaction with the surface. This leads to different interactions of the ion of 1 
beam with the sample surface and some new effects can be generated and used in the the 
samples treatments [5]. Because ions are much larger than electrons, they cannot easily The 
penetrate within individual atoms of the sample. Interaction mainly involves outer shell pre 
interaction resulting in atomic ionization and breaking of chemical bonds of the sample's etc 
atoms. This creates secondary electrons and change of chemical state in the surface region rec 
of the sample. Since the inner shell electrons of the sample cannot be reached by the car 
incoming ion, there is no x-ray emission when the sample is irradiated with an ion beam. mo 
Additionally, the penetration depth of the ions is much lower than the penetration of the gra 
electrons of the same energy. Finally, the ion surface interaction can be accompanied by an De 
efficient and rapid sputtering which makes the FIB a unique instrument which is capable of gra 
in-situ microscopic milling and machining [6-8]. Namely, when the ion hits an atom, its mass por 
is comparable to the mass of the sample atom and as a consequence it will transfer a large hig 
amount of its energy to the atom which starts to move with a speed and energy high enough frol 
to remove it from its matrix. In practical applications this effect can be used for sample x the 
polishing, etching and 3D microscopy. Additionally, when a focussed ion beam system is Thy 
extended with a SEM column ion beam it can be used also for high resolution imaging [9]. the 
In this paper we present the results of microstructural characterisation of rapidly solidified Cu ten 
— Zr ribbons prepared by different preparation methods. The microstructures prepared by thre 
standard metallographic technique were compared with those obtained by focussed ion for 
beam (FIB) technology.