Abstract: An apparatus and method of mechanical milling and grinding of various materials at temperatures ranging from sub-ambient conditions to well-below their ductile-brittle transition temperature (DBTT) are presented. In one embodiment the present invention entails the design of a cryogenic milling chamber compatible with horizontal high-energy mills. The new design and configuration of the milling vessel provides robust and efficient cryomilling of various materials with no contact between the cryogen and the powders. Some embodiments of the invention improve the heat removal rate from the non-uniform heat load generated by the impact energy deposited into the chamber wall by the milling media.

Abstract: An apparatus and method of mechanical milling and grinding of various materials at temperatures ranging from sub-ambient conditions to well-below their ductile-brittle transition temperature (DBTT) are presented. In one embodiment the present invention entails the design of a cryogenic milling chamber compatible with horizontal high-energy mills. The new design and configuration of the milling vessel provides robust and efficient cryomilling of various materials with no contact between the cryogen and the powders. Some embodiments of the invention improve the heat removal rate from the non-uniform heat load generated by the impact energy deposited into the chamber wall by the milling media.

Abstract: Novel metallic systems and methods for their fabrication provide high temperature machine parts formed of a consolidated nano-crystalline metallic material. The material comprises a matrix formed of a solvent metal having a melting point greater than 1,250° C. with crystalline grains having diameters of no more than about 500 nm, and a plurality of dispersed metallic particles formed on the basis of a solute metal in the solvent metal matrix and having diameters of no more than about 200 nm. The particle density along the grain boundary of the matrix is as high as about 2 nm2 of grain boundary area per particle so as to substantially block grain boundary motion and rotation and limit creep at temperatures above 35% of the melting point of the consolidated nano-crystalline metallic material. The machine parts formed may include turbine blades, gears, hypersonics, radiation shielding, and other high temperature parts.

Abstract: Novel metallic systems and methods for their fabrication provide high temperature machine parts formed of a consolidated nano-crystalline metallic material. The material comprises a matrix formed of a solvent metal having a melting point greater than 1,250° C. with crystalline grains having diameters of no more than about 500 nm, and a plurality of dispersed metallic particles formed on the basis of a solute metal in the solvent metal matrix and having diameters of no more than about 200 nm. The particle density along the grain boundary of the matrix is as high as about 2 nm2 of grain boundary area per particle so as to substantially block grain boundary motion and rotation and limit creep at temperatures above 35% of the melting point of the consolidated nano-crystalline metallic material. The machine parts formed may include turbine blades, gears, hypersonics, radiation shielding, and other high temperature parts.