Prakt. Met. Sonderband 38 (2006) 167 
urface is 
nerringly 
) makes 
surfaces. 
and also 
1 not be 
ta 2um 
obtain a 
urs. After 
shed 3-D 
is the Pt- 
f the SE 
ture. On 
h a poor 
3-etching Figure 5: 3-D microscopy of an alloy 2 melt-spun ribbon; a) 3D cross-section after sputtering 
rich ion and FIB-polishing; b) After 38 min FIB-etching at 10 pA. 
4 CONCLUSIONS 
FIB is an adequate tool to perform the metallographic preparation of melt-spun Cu-Al-Ni 
ribbons. Most of difficulties coupled with conventional preparation can be avoided. The 
major disadvantage of in-situ FIB preparation may be the disability to cut, polish and etch 
large areas. 
From our experience, for FIB-etching rather small ion-currents should be preferred if fine 
microstructural details are to be revealed. In preliminary work with melt-spun Cu-Al-Ni 
ribbons a current of 10 pA turned out to be a good compromise between the revealed details 
and the necessary time for areas of about 25 to 100 um?. But, as the area to be etched 
increases, the time required to obtain a satisfying result increases enormously. Besides, we 
assume, that the bright thin horizontal lines, which can be observed in Figure 2b inside of 
large smooth evenly coloured areas of y, could be a consequence of too low selected 
current (and thereby too small beam diameter) to evenly “cover” the surface of the area. 
It was exposed, that the efficiency of FIB-etching is higher on smooth surfaces. If the surface 
was too rough, the microstructural features can be concealed by the topographic features of 
ring and the surface. 
In 3-D microscopy the application of the FIB-deposited Pt-compound protective layer brings 
advantages as well as disadvantages. If the edge should be straight and sharp and the 
ering the surface of the 3-D cross-section smooth, then the protective layer is unavoidable. But, if 
ers were applied, the free surface of the sample cannot be seen. If the surface surrounding the trench 
ce of Pt- should be observed too, most likely the “curtains” and rounded edge will have to be 
the two- accepted. 
je of the 
tical ribs 
present. 
n already 
36S. The