Abstract:
Sequential casting is a facile and fairly new technique to produce functionally graded materials
(FGMs) and components by controlled mold filling process. In the present investigation,
functionally graded bimetallic aluminum alloys are produced by sequential gravity casting using
A390–A319 and A390–A6061 alloy combinations. The control in pouring time between two
melts has shown a significant effect on the quality and nature of interface bonding. The
microstructure reveals good interface miscibility achieved through diffusion bonding between
the alloys. A higher hardness of 160 BHN in the A390 region is obtained in both sequential cast
systems, and a minimum value of 105 and 91 BHN is observed in the A319 and A6061 regions,
respectively. The tensile and compression strength for A390–A319 are 337 and 490 MPa,
whereas for A390–A6061, they are 364 and 401 MPa, respectively, which are significantly higher
compared with the standard values of the base alloys, which confirms strong interface bonding.
The A390 region shows higher wear resistance compared with other regions of the sequential
cast system. The process described in this study is a potential and efficient approach to create
good bonding between two different aluminum alloys to develop advanced functional and
structural materials.
