PRODUCTION OF HIGH-SPEED FLYING BODY MADE OF TUNGSTEN ALLOY

摘要

PURPOSE:To produce a high-speed flying body made of a W alloy having excellent ductility by compacting a powder mixture consisting of a specific ratio of W and the balance Ni and Fe, sintering the molding in a liquid phase and working the sintered body to a final shape then heating the body in a vacuum and quickly cooling the same. CONSTITUTION:The powder mixture consisting of 85-97% W, and the balance Ni and Fe is compacted under about 1-4ton/cm2 hydrostatic pressure. The resultant green compact is sintered in the liquid phase at least at about =1,450 deg.C in gaseous hydrogen flow kept at about 0 dew point - -60 deg.C, by which the green compact is additionally compacted. Fe is preferably incorporated at about 20-50% in the above-mentioned binding phase consisting of Fe and Ni. The sintered body obtd. in the above-mentioned manner is worked by machining, etc. to substantially the final shape. The worked body is thereafter subjected to a heat treatment by heating in a vacuum, then quick cooling. The above-mentioned heating is preferably executed by holding for about 2-10hr at about 700-1,400 deg.C to remove the solutionized hydrogen. The quick cooling is executed at about =40 deg.C/min cooling rate down to about 300 deg.C to form the good structure.