Magnesium for Aircraft Construction

Abstract

T E use of magnesium alloy as a material for aircraft construction has increased rapidly in the last few years. Castings and forgings are in common use, and a small amount of sheet and extruded stock is being used for cowlings, fairings, and interior furnishings. Litt le attention, however, has been paid to the possibility of using magnesium for the main structure. I t is likely t ha t most designers feel t ha t the use of magnesium alloy in the conventional semimonocoque construction offers too many difficulties from the corrosion standpoint. In reality, magnesium alloy sheet may be successfully used except when subject to frequent immersion in sea water. The Bureau of Standards report on five-year atmospheric exposure tests a t Coco Solo states tha t , Magnesium panels were in unexpectedly excellent condition I t may be concluded tha t magnesium alloy could doubtlessly be used successfully for prolonged periods in the tropics, particularly if occasional inspection and repair on the paint coating were possible. This paper deals with the possibility of substi tuting magnesium alloy for aluminum alloy in certain types of airplane structures, thereby saving weight, and /o r decreasing the cost of production. I t gives the results of static tests on a monocoque magnesium tail surface and several sheet-stringer panel tests, and indicates the research which must be done before the manufacturer is warranted in adopting such material for production.