Open AccessA comparative study between the addition of NH4Cl and KCl in NaNO3 and NaF-based degassers in aluminum casting
Author(s) -
Donanta Dhaneswara,
Jaka Fajar Fatriansyah,
Agatha Rona Basa
Publication year - 2019
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/578/1/012065
Subject(s) - sodium nitrate , casting , porosity , aluminium , materials science , solubility , metallurgy , chemistry , chemical engineering , composite material , engineering
The quality of Al-Si casting product is important for its applications, however the molten aluminum has high solubility of H 2 at melting temperature in the casting process, so the formation of gas porosity during aluminum solidification is inevitable. This can cause a major drawback to the mechanical properties. The most common method to remove hydrogen gases in the molten metal is degassing. In this experiment, a conventional degassing method using Sodium Nitrate-Sodium Fluoride based degasser is conducted. Al-Si12 was melted at 720 °C then the degasser was plunged into the furnace bottom and held for three minutes. The results show better mechanical properties by the addition of degasser. This is because the degasser binds H 2 gases which is formed in the melting process. The mechanical properties between casting products that use NaF-NaNO 3 degasser and NaF-NaNO 3 with addition of NH 4 Cl or KCl were measured and compared. The lowest mechanical properties were obtained when using degasser without NH 4 Cl or KCl. This is because NH 4 Cl or KCl is reactive and helps with the efficiency of degasser.