Pembentukan lapisan intermetalik pada penambahan unsur mangan 0,1%, 0,3%, 0,5%, 0,7% dalam paduan Al-7% Si dan Al-12% Si di material H13 dengan perlakuan over tempering = Intermetallic layer formation in addition elements Mangan 0.1%, 0.3%, 0.5%, 0.7% in alloy Al-7% Si and Al-12% Si in material tempering H13 with over treatment