Investigation of the Properties of Consolidated Forms of Light Alloys Produced From Ultrafine, Nano-, and near-Nano Size Powders in PM (spark plasma sintering, hot isostatic processing) Operations

Ultrafine, near-nano and nano-grained materials consolidated in Powder Metallurgical (PM) operations show considerable potential for use in the aerospace industry.  The Hall-Petch relationship cites the strengthening of materials by reducing the average crystallite (grain) size.  A study is proposed to investigate the increase in mechanical properties provided by ultrafine, near-nano and nano-grained powders of aluminum and titanium alloys used in powder metallurgical consolidation operations.   Ultrafine, near-nano, and nanocrystalline powders of light alloys are produced from attrition milling (at cryogenic conditions) operations.  Further, fine nitride particles are added to several batches milled materials to investigate the influence of the nitrides to the material properties.  Consolidated forms of ultrafine, near-nano and nanocrystalline materials will be produced using hot isostatic pressing (HIPing), Spark Plasma Sintering (SPS) or vacuum sintering.    The mechanical properties of the ultrafine, near-nano and nanocrystalline materials will be compared to consolidated forms of conventional materials.  The milled and blended powders, and consolidated forms produced from these powders will be examined using Field Emission Scanning Electron Microscopy to investigate the microstructures produced.  Macrohardness, microhardness, shear testing, tensile testing and compression testing will be performed to examine the mechanical properties of selected consolidated form of these materials.