THE EFFECT OF FINE COAL IN TUBE MOLDS WHEN POURING ALUMINUM ALLOY 6061 ON WEAR RATE AND HARDNESS VALUE

Abstract

Aluminum alloy 6061 material, which is widely used in daily life, has been melted in a crucible.
The pouring of aluminum liquid is carried out into a cylindrical tube that functions as a mold, which has already
been filled with finely ground and sifted sub-bituminous coal. Due to the temperature difference is large enough,
fine coal has burned, and combustion products will react to the aluminum alloy. The results of the Brinell
hardness test and the Ogoshi method wear have been influenced by three main elements of coal combustion,
namely moisture content, volatile matter, and fixed carbon. The addition of fine coal has reduced hardness
values. The addition of at least 12.5 grams of fine coal has reduced hardness from 31.66 BHN to a very
minimum of 29.90 BHN. However, when fine coal has been added again, it has increased the value of hardness.
Wear rates have increased with the addition of fine coal combustion, but with the amount of fine coal increasing
again, the wear rate have decreased. The addition of at least 12.5 grams of fine coal has increased the wear rate
to a maximum, i.e., from 5.20E-07 mm2
/kg to 7.25E-07 mm2
/kg. The addition of at least 12.5 grams of fine
coal has increased the wear rate to a maximum, i.e., from 5.20E-07 mm2
/kg to 7.25E-07 mm2
/kg