Accession Number : AD0014005
Title : STUDY OF HARD COATING FOR ALUMINUM ALLOYS
Descriptive Note : Technical rept.
Corporate Author : CORNELL AERONAUTICAL LAB INC BUFFALO NY
Personal Author(s) : GILLIG, F G
Report Date : May 1953
Pagination or Media Count : 121
Abstract : A study was made of the effects of the hard oxide coatings produced by the Martin Hard-Coat process on the properties of 5 wrought and 2 cast Al alloys. Coating thicknesses ranged from 0.0005 to 0.005 in. The abrasion resistance of the coatings and the effect on the fatique strength of the parent metal were the most critical properties. The abrasion resistance substantially exceeded that of coatings produced by standard amodizing treatments and was equal to or better than that of thin cyanide coatings on steel. The coatings imparted corrosion resistance to Al alloy surfaces. The abrasion resistance decreased with exposure to humidity and atmospheric conditions; subsequent treatment, other than with boiling H2O which is used to seal anodized coatings, is expected to prevent the resistance decrease. The coatings lowered the fatigue strength of the metal by up to 65%; the decrease was not proportional to coating thickness.
Descriptors : *METALS , *ALLOYS , *COATINGS , THICKNESS , EXPOSURE(GENERAL) , STRENGTH(MECHANICS) , SURFACES , CORROSION RESISTANCE , OXIDES , FATIGUE(MECHANICS) , THINNESS , CYANIDES , HARDNESS , SEALS(STOPPERS) , ANODIC COATINGS , HUMIDITY , WEAR RESISTANCE
Subject Categories : Metallurgy and Metallography
Distribution Statement : APPROVED FOR PUBLIC RELEASE