I do not know the eutectic point.  I do know that in at least 5
different semiconductor manufacturers I worked in we alloyed aluminum to
silicon at about 435 degree C in a reducing atmosphere.  It led to the
manufacture of our 450 degree C oven with reducing gas control.

Bill Moffat, CEO
Yield Engineering Systems, Inc.
2185 Oakland Rd., San Jose, CA  95131
(408) 954-8353