Abstract :
On inspection of the PK-SFA aircraft, cracks were found on the fork nose
landing gear. The position of the Fork is attached to Ferrule, conditions like this
are closely related to galvanic corrosion and can trigger cracks or failures in
components that can endanger the safety of the aircraft. Corrosion itself is caused
by the interaction of metal with metal and the surrounding environment.
The purpose of this study was to determine the rate of galvanic corrosion
between fork and ferrule materials in 3.5% NaCl media with variations in
immersion time using a rectifier. The test object is made into a square shape and
then polished to get a clean surface from the coating. Prior to the corrosion test,
each component material is tested for composition to determine the type of material.
The corrosion rate was analyzed using the weight loss method and the potential
difference method. Another test carried out to support this research is the Micro
Test of the surface of the material that has been tested for corrosion.
The results of the composition test showed that the content of Magnesium
(Mg) was 2.087% and Zinc (Zn) was 5.411% and the content of Aluminum (Al) was
90.65% and there were other guiding elements. And produced Grade Al100 for
ferrule components. In the Fork component, the carbon content is 0.388% and the
Iron (Fe) content is 95.78% and there are other guide elements that are low, then
Grade Fe110. The corrosion rate that is generated from the calculation of the
potential difference method is for the 4th minute = 0.759 volts/minute, the 6th
minute = 0.506 volts/minute, and the 8th minute = 0.379 volts/minute. The value of
the corrosion rate obtained by the weight loss method of Al material is 1.057 mmyr,
specimen 2 is 709 mmyr, 3 is 2.453 mmyr, and for Fe material, specimen 1 is 1.510
myr, specimen 2 is -2.908 mmyr, specimen 3 amounted to 1.361 mmyr.