PERUBAHAN NILAI KEKERASAN DAN STRUKTUR MIKRO BAJA AISI H13 AKIBAT VARIASI ARUS PADA PROSES ELECTRICAL DISCHARGE MACHINING(EDM)SINKING MENGGUNAKAN ELEKTRODA GRAFIT
Abstrak: EDM (Electrical
Discharge Machining) is the process of the workpiece with a spark jumps that
occur in the gap between the electrode and the workpiece is immersed in a
dielectric fluid and occur periodically. Material for die casting mold is generally
made of tool steel (Tool Steel) AISI type H13 is processed using the EDM. This
material is well known of its hardness and its toughness. The research ai is to
determine current of EDM in finding the best hardness and its microstructure.
In this study the current was varied 6, 9 and 12 amperes. While the other
parameters held constantly. Observation shows that the highest hardness value
of 689 VHN in the white layer when the current applied is 12 amperes. Whereas,
the lowest hardness of 388.6 VHN at the side when using current of 6 amperes.
The higher the current applied, the higher the temperature of the process.
Consequently, it would enriched the carbon from melting electrode and
dielectric fluids in the white layer, At last, the formed layer will contain
more carbon than carbide (Fe 3 C). In fact, increasing hardness in the white layer
was not followed by increasing hadrness in the layer below white layer as the heat
was quickly removed by dielectric fluid. The recommended current to be used is
6 ampere; eventhough the hardness of the white layer is not optimum one but the
white layer formed is the continous one. In fac, the continous white layer
promising the longer life time of the mold.
Penulis: Ronny Prastya
Aditama, Mahros Darsin, Sumarji
Kode Jurnal: jptlisetrodd120269
