A STUDY OF THE FLAMMABILITY OF MAGNESIUM

An investigation of the ignition and burning characteristics was conducted on prepared specimens of four common magnesium alloys. In addition, typical reciprocating engine castings were tested to determine ignition and burning characteristics under fire conditions closely representing the intensity of an aircraft power plant fire. The major results of the prepared specimen tests are presented as a family of curves which indicate that time to ignition did not vary significantly among the alloys tested, but varied directly with thickness of specimen and airflow over the specimen. After ignition, the airflow accelerated the alloys burning rate. Tests on the castings revealed a minimum time to ignition of 2 minutes for the smallest 23 pounds and 4 minutes for the largest 91 pounds. In general, tests indicated that it would be good practice to eliminate sharp edges and protrusions from magnesium alloy castings where possible since these areas were observed to be more susceptible to ignition. Small magnesium components that are not an integral part of the engine could represent a substantial fire hazard in that they will ignite in a short period of time under intense fire conditions.