1. All of Al-Mg-Sn PM alloys considered in this study
were responsive to sintering and the majority could
be sintered to >98.8 pct of their full theoretical
value.
2. The microstructures of all PM alloys included aluminum
grains, Mg2Sn, and in select instances elemental
tin.
3. As the bulk content of Mg was increased, so too
did the amount of Mg within the aluminum grains.
However, Sn impeded the diffusion of Mg into the
aluminum grains through a reaction that prompted
the formation of Mg2Sn.
4. Heat capacities of the PM materials increased in a
systematic manner with temperature, yet the bulk
alloy chemistry did not have a clear effect.
5. Increasing concentrations of magnesium had a negative
influence on thermal diffusivity and thermal
conductivity, whereas tin concentrations had an
opposing effect. This behavior was directly attributable
to the influence of each element on the concentration
of magnesium dissolved within the
aluminum grains.
6. The PM alloy Al-0.6Mg-1.5Sn exhibited a nominal
thermal conductivity of 225 W/m K. This was the
highest value measured for the PM systems
assessed. Such conductivity was comparable to
wrought heat sink materials and highly advantageous
over those that are die cast.