Abstract:
A method of effective recycling of aluminium castings suitable for small foundries
was investigated. Automotive cast aluminium scrap obtained from various scrap
vendors was sorted into groups of similar components, namely; pistons, cylinder
heads and housings (gearbox and rear-axle housings). This sorting method was
adopted with the hypothesis that the resulting alloys could be closely equivalent
to the commercial alloys that were originally used to make the components. The
remainder of the scrap was grouped as miscellaneous scrap and contained various
parts such as alternator covers, exhaust manifolds, oil sumps and other assorted
scrap.
As hypothesised, the chemistry of the resulting alloys were found to be
consistently equivalent to the commercial alloys commonly used to cast the various
components that were melted. For example, the alloy chemistry of secondary alloys
from piston scrap was consistently equivalent to commercial piston alloys such as
AC8B and LM26. Furthermore, alloys from cylinder head scrap were equivalent
to commercial alloys such as 319, LM27 and AC2B. On the other hand, the alloy
chemistry from unsorted scrap was not found to be consistent nor equivalent to
a specific group of commercial alloys except for the 319 and 380.0 workhorse
alloys. These results are discussed against the possibility of reusing the alloys in
casting components similar to those that they were recycled from, in addition to
other possible applications.
