Abstract :
The use of aluminum in the automotive industry has continued to increase
since 1980 especially aluminum alloys used for the manufacture of cylinder heads,
pistons, valves, and engine blocks. The use of scrap metal as industrial raw
materials is increasing so that it becomes a trading commodity and encourages the
development of scrap metal or scrap metal storage businesses around the business
location.
This study aims to investigate the value of tensile strength, hardness,
microstructure, and chemical composition of the effects of variations in the
remelting temperature of the pistons of used Kawasaki Ninja motorcycles using the
sand-casting method. The specimens and tensile testing procedures refer to the
ASTM E8/E8M-09 standard.
The result of this study indicated that the higher the temperature pour, the
value of the tensile strength of the castings also increased. The highest tensile
strength value was obtained at a casting temperature of 850? (specimen C) in
87,74 MPa, while the lowest tensile strength value was found at a casting
temperature variation of 750? (specimen A) in 61,27 MPa. The highest Vickers
hardness value was found at a casting temperature of 850? in 105,49 VHN, while
the lowest Vickers hardness value was found at the casting temperature variation
of 750? in 91,22 VHN. It could be observed that the particle structure becomes
denser and finer as the pouring temperature increases. The results of the chemical
composition test carried out showed an increase and decrease in the chemical
elements contained in the casting material. This could be caused by the effects of
the pouring speed, the together process of disassembling the mold carried out, and
the different moisture content of the sand mold.