I {he MIC 
Am 
pA 
Rem 
Ihe am : 
Fig.10: Slowly solidified Al-28.2 Fig.11: Rapidly solidified Al-28.2 ii 
wt% Ni. SEM electron micrograph wt% Ni. Optical micrograph x150. oo 
(composition image x150). SO. 
ahs 
Temary fl 
sung tun 
When de 
Fig.12: Slowly solidified Al-31.4 Fig.13: Rapidly solidified Al-31.4 To 
wt% Ni. SEM electron micrograph wit% Ni. Optical micrograph x500. RET 
(composition image x150). 
This latter compound went on to crystallize down to 640°C when the remaining eutectic liquid 
got frozen. If rapidly solidified by melt extraction all Ni rich Al-Ni alloys pointed to drastic 
modifications in their microstructure (fig.9,11,13). All of them show a very fine dispersion of extremly 
small Al;Ni particles embedded in the matrix consisting of the supersaturated atAl solid solution. 
The microstructure obtained by rapid solidification in the Ni rich Al-Ni alloys is of great 
practical interest. Actually the fine AlsNi particles, if separated by an alkaline solubilization of the 
matrix, have an extremely large specific area that provides them with good catalytic properties in 
hydrogenation reactions of organic substances [2]. Co 
The value 
Weis: 
REFERENCES 7 
(1) Lidia Cristea,”Doctoral Thesis”, University “Politehnica” of Bucharest, (1998). 
(2) Lidia Cristea, N. Petrescu, “Sci.Bull.Univ. “Politehnica” of Bucharest, seriesB, vol.61., no.3-4, 
(1999). 191 
754