TEMPERATURE STRENGTH VIA RAPID SOLIDIFICATION TECHNOLOGY

A SCREENING PROGRAM WILL BE CONDUCTED TO IDENTIFY NEW TITANIUM ALLOYS HAVING IMPROVED MECHANICAL PROPERTIES FROM ROOM TEMPERATURE TO 1400 DEG F. THESE ALLOYS WILL BE PRODUCED USING MARKO'S PROPRIETARY RAPID SOLIDIFICATION TECHNIQUE, FOLLOWED BY PULVERIZATION, CONSOLIDATION BY HOT ISOSATIC PRESSING AND EXTRUSION, AND THERMAL STABILIZATION. TWENTY-SIX COMPOSITIONS WILL BE STUDIED BASED ON THE INTERMETALLIC COMPOUNT TI(3)AL STABILIZED WITH NIOBIUM AT 5 AND 15 ATOMIC PERCENT TO PRODUCE A SINGLE PHASE ALPHA, AS WELL AS A TWO PHASE (ALPHA + BETA) ORDERED STRUCTURE. TIN, ZIRCONIUM, AND HAFNIUM WILL BE ADDED TO DETERMINE THEIR EFFECT O MICROSTRUCTURE AND DUCTILITY AS WELL AS VARIOUS LEVELS OF SILICON, BORON, CARBON, AND ERBIUM TO DETERMINE THEIR EFFECT ON DISPERSION STRENGHTENING AND GRAIN REFINEMENT. APPROPRIATE THERMAL STABILIZATION HEAT TREATMENTS WILL BE ESTABLISHED. MICROSTRUCTURAL EVALUATIONS WILL BE PERFORMED ON ALL ALLOYS IN THE AS-CAST, AS-EXTRUDED, AND THERMALLY STABILIZED CONDITION. SUFFICIENT QUANTITY (2 LBS) AT LEAST TWELVE ALLOYS WILL BE PRODUCED TO PERMIT TENSILE TESTING AT ROOM TEMPERATURE AND 1300 DEG F.