ALUMINIDE P/M ALLOYS

RAPIDLY QUENCHED ALUMINIDE ALLOYS ARE OF IMPORTANCE IN POWER METALLURGICAL (P/M) FABRICATION OF LIGHT WEIGHT HIGH STRENGTH STRUCTURAL PARTS INTENDED FOR USE IN ADVANCED AEROSPACE SYSTEMS. THE ULTIMATE MECHANCIAL PROPERTIES OF THESE COMPACTED PARTS DEPENDS CRITICALLY ON THE OXIDE SKIN OF THE POWDERS AS OBTAINED FROM DIRECT POWDER QUENCHING OR GRINDING OF RAPIDLY SOLIDIFIED RIBBON MATERIAL. THE BRITTLE OR DUCTILE PROPERTIES OF THE OXIDE WILL DETERMINE HOW WELL IT CAN BE BROKEN UP EITHER THROUGH MECHANICAL ATTRITION OR WHEN THE POWDER UNDERGOES HOT SHEAR CONSOLIDATION. MAXIMUM DESTRUCTION OF THE OXIDES IS IMPORTANT PRIOR TO OR DURING THE COMPACTING OF THE POWDERS. THIS EFFECT CAN OCCUR THROUGH A CRUMBLING ACTION OF THE OXIDE SKIN AND DIRECT INCORPORATION OF THE PARTICULATES INTO THE COMPACTED ALLOY THEREBY ADDING PARTICULATE DISPERSANT STRENGTHENING. THE OBJECTIVE OF THE PROPOSED RESEARCH IS TO DEVELOP MECHANICA, CHEMICAL, AND/OR PHYSICAL METHODS FOR TREATING THE OXIDE IN ORDER TO MODIFY ITS DUCTIBILITY PROPERTIES. THIS WILL INITIALLY BE APPROACHED BY DEVELOPING METHODS FOR EVALUATING AND ANALYZING THE OXIDE SKINS. THE RESULTS OF THIS WORK WOULD HOPEFULLY LEAD TO A MODIFIED VERSION OF DEGASSING BY HEAT TREATMENT RESULTING IN A LESS ADVERSE EFFECT ON SECOND PHASE DISPERSANTS IN THE RAPIDLY SOLIDIFIED MATERIALS.