MIL-PRF-25134C(USAF)
Four each
-
Aluminum alloy 2024-T3, ASTM B209
Four each
-
Aluminum 1100-H24, ASTM B209
The steel, tinplate, and aluminum panels shall be washed with a suitable solvent after which they
shall be cleaned with acetone-wet pumice and rinsed with methyl alcohol. The magnesium panels
shall be rinsed with acetone.
4.7.9.2 Single panel corrosion test. The steel, tinplate, and two each of the 2024 and 1100
aluminum panels shall be accurately weighed, placed singly at approximately a 45° angle in the
smallest practicable jars, and completely submerged in remover. The jars shall be tightly sealed
and placed in an oven maintained at 100° 3°F. At the end of 168 hours at temperature, the
samples shall be removed and brushed as necessary to remove difficult residue. The panels shall
then be cleaned with a suitable solvent, dried, and weighed. Any pitting, etching, or change in
weight exceeding the following limits shall be considered as indicating corrosion and shall be
grounds for rejection of the material:
±1.0 mg
±0.3 mg
Steel
2024 aluminum alloy
±0.4 mg
±0.3 mg
Tinplate
1100 aluminum
4.7.9.3 Corrosion test for dissimilar metal.
4.7.9.3.1 Coupling of dissimilar metal test panels. The two remaining 2024 aluminum alloy
panels prepared in accordance with 4.7.9.1 shall be coupled to the panels of magnesium alloy
treated in accordance with MIL-M-3171, Type III. The two remaining 1100 aluminum panels
(4.7.9.1) shall be coupled to the panels of magnesium alloy treated in accordance with MIL-M-
3171, Type I. The size and placement of holes required for coupling shall be in accordance with
Figure 1. The panels shall be positioned and assembled in accordance with Figure 2 and coupled
with cadmium plated steel screws, washers, and nuts as indicated below:
a. Screws, MS35206-232, except plating shall be QQ-P-416, Type I, Class 1.
b. Washers, NAS 1149, except plating shall be QQ-P-416, Type I, Class 1.
c. Nuts, MS35649-262, except plating shall be QQ-P-416, Type I, Class 1.
The assemblies shall be tightened to 6 inch-pounds torque. The contact area shall be
approximately one square inch. Each couple shall be checked to insure good electrical continuity.
4.7.9.3.2 Procedure. The coupled panels shall be placed at an angle (approximately 45°) in
separate jars of the smallest practicable size after which they shall be completely submerged in
remover. The jars shall be tightly sealed and placed in an oven maintained at 100° 3°F for a
period of 72 hours. The panels shall then be removed and immediately suspended vertically for 72
hours in a desiccator. Prior to the test, the desiccator shall be cleaned and the lower portion filled
with distilled water after which it shall be closed and conditioned at 77° ± 2°F. During the test
the desiccator shall be kept tightly sealed in an area maintained at 77° ± 2°F. At the end of the 72
11
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business