Nanocrystalline Aluminum Alloys Thermally Stabilized with Diamantane Hydrocarbons

ABSTRACT.

A type of aluminum alloy; 5083-Aluminum alloy is investigated for optimal structural applications in the aerospace industry. The goal is to enhance the mechanical property of the Al alloys by to reducing the grain size for the optimization of a higher yield strength and better thermal stability material. The general process of achieving a reduced grain size up to the nanometer scale involves cryomilling with steel balls, Hot Isostatic Pressing (HIP), Trap Extrusion, and Microscopic analysis.  Milling with the steel balls is done at a cryogenic (low) temperature; it allows the crystalline materials to become brittle, and thereby allowing the smoothing grinding process for the aluminum to turn into a fine powder.  HIP sinters the powder with a noble gas at high pressure and temperature to eliminate porosity in the aluminum alloy, hence turning it into a bulk material.  After the aluminum alloy gets to the bulky material stage, the thermal stability becomes limited. Diamantine of different concentrations is added to the Al alloy to enhance thermal stability and prevent grain growth that happens with the application of heat on the aluminum.