Peningkatan Sifat Mekanik Paduan Aluminium A356.2 Dengan Penambahan Manganese (Mn) Dan Perlakuan Panas T6

Aluminum Alloy A356.2 is one of aluminum alloys that is suitable to be used as a car wheel - rim material. This is because it has some benefits such as lightweight material, corrosion resistance material, interesting color but its mechanical properties do not meet criteria of JIS H 5202. For that reason, to meet the standard its mechanical properties need to be improved. Mechanical properties of this alloy can be improved using many ways; one of these is by changing its chemical composition. In this research, Mn element is added to alloy A356.2 containing Mn 0.05%w originally. Mn addition to the alloy is commenced from the amount of 0.2%w, 0.4; 0.6; 0.8; 1.0; 1.2; 1.4 and finally 1.6%w. After this, some tests are conducted to these new alloys including tensile test, hardness test, impact test and micro - structural test. Test results show that the change of material mechanical properties occurs due to Mn addition and heat treatment T6 to these alloys. The optimum mechanical properties are obtained with the addition of 1.2%w Mn to the alloy. In this condition, the alloy has Ultimate Tensile Stength of 31.58 kg/mm2, elongation of 7.54%, hardness test of 90.74 HVN and impact test of 5.88 J/cm2 and these results fulfill JIS H 5202 standard