Compact AM50 alloy components were cast by Low Pressure Die Casting (LPDC)
process. The microstructure and mechanical properties of cast components were investigated under
as-cast and heat treated states. It was found that the microstructure of LPDC AM50 is composed of
α-Mg and second phases - Mg17Al12 and Al8Mn5. Compared with Gravity die casting, LPDC AM50
alloy had much coarser grains and higher density, with smaller sizes and less content of second
phases. The density of AM50 alloy by LPDC process was ρ=1.7836g/cm3, with increase of 0.45%
based on Gravity die casting and much more increase compared with high pressure die casting. The
as-cast mechanical properties by LPDC process were: σ0.2=57.8Mpa, σb=192.3Mpa, δ=8.7%. These
of Gravity die casting were: σ0.2=53Mpa, σb=173.4Mpa, δ=8.1%. UTS in LPDC increased about
20MPa, with better YTS and Elongation. Compared with that of high pressure die cast AM50, the
YTS of LPDC was much lower, with comparable UTS and Elongation. The mechanical properties of
the heat treated AM50 alloy were still in the same level of as-cast state. AM50 alloy by LPDC process
is not necessary subjected to tempering treatment.
Effect of heat treatment and Fe content on the microstructure and mechanical properties of die-cast Al–Si–Cu alloys