S. M. El-Soudani, The Boeing Company, Huntington Beach, CA; M. Campbell, J. Phillips, Plymouth Engineered Shapes, Hopkinsville, KY; V. S. Moxson, V. Duz, ADMA Products, Twinsburg, OH
The feasibility of canless extrusion in ambient environment of hydride/dehydride blended elemental Ti-6AL-4V ADMA-processed powder previously direct-consolidated by cold isostatic pressing (CIP), followed by vacuum sintering has been successfully demonstrated. In these extrusion process trials at Plymouth Engineered Shapes the extrusion processing sequence and parameters used were essentially similar to those used for billets prepared from wrought ingot-based Ti-6AL-4V material. Boeing Laboratory analysis showed that the canless powder-based billet extrusion processing step conducted in air added no more than 200 ppm oxygen to the as-vacuum-sintered billet oxygen content. Preliminary tensile properties of the blended-elemental ADMA powder-based extrusions of a Ti-6AL-4V composition processed both in the beta or alpha-beta ranges of extrusion temperatures showed equivalent or superior tensile properties as compared to identically processed wrought, ingot-based and extruded Ti-6AL-4V billet materials. In the blended elemental powder-based extrusions both nitrogen and carbon contents were within specification limits for Ti-6AL-4V alloy, while any excessive residual hydrogen was successfully vacuum degassed after extrusion to within specification limits. Further optimization for fracture toughness, stress-corrosion resistance and fatigue properties will build on these encouraging results, while monitoring and controlling the only remaining powder-based interstitial element, namely oxygen uptake during pre-extrusion powder-consolidation processing steps.
Summary: this will be submitted at a later date
