Accession Number : ADA626279


Title :   Deformation Driven Alloying and Transformation


Descriptive Note : Final rept. 5 Dec 2011-4 Dec 2014


Corporate Author : WISCONSIN UNIV MADISON


Personal Author(s) : Perepezko, John H


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a626279.pdf


Report Date : 03 Mar 2015


Pagination or Media Count : 72


Abstract : The findings on deformation driven phase reactions in isomorphous systems such as Cu-Ni and Ag-Pd indicate that new kinetic pathways can be exposed that are fundamentally different than those that control conventional thermal annealing where interdiffusion creates a smoothly varying composition profile that leads to a homogeneous solid solution. Under deformation driven interfacial mixing, the composition profile develops an oscillation with an average composition close to the overall multiplayer composition. The amplitude of compositional oscillation decays with further deformation until a uniform solid solution is created. It was also observed that the component mixing rates during deformation driven mixing are opposite to those that occur during thermal interdiffusion. Further findings on eutectic systems such as Ni-V and an immiscible system like Cu-Fe also indicate a supersaturated solid solution phase develops during deformation with the suppression of the nucleation and growth of intermediate phases. In fact, FCC V-rich and BCC Ni-rich solid solutions in bulk volumes were synthesized by intense deformation. This is a new behavior that has not been reported previously and appears to be a new feature of mechanochemical transduction. It could also provide new kinetic pathways and the synthesis new microstructures that cannot be made by conventional thermally activated diffusion. Further study of the underlying mechanisms is warranted.


Descriptors :   *COPPER NICKEL ALLOYS , *DEFORMATION , *NANOCRYSTALS , ALLOYS , AMPLITUDE , ANNEALING , EXPOSURE(GENERAL) , GROWTH(GENERAL) , HEAT , HOMOGENEITY , KINETICS , MICROSTRUCTURE , NUCLEATION , OSCILLATION , PALLADIUM ALLOYS , PHASE TRANSFORMATIONS , SCANNING ELECTRON MICROSCOPES , SILVER ALLOYS , SOLID PHASES , SUPERSATURATION , SUPPRESSION , SYNTHESIS(CHEMISTRY) , THERMAL PROPERTIES , X RAY DIFFRACTION


Subject Categories : Organic Chemistry
      Metallurgy and Metallography
      Crystallography
      Mechanics
      Solid State Physics


Distribution Statement : APPROVED FOR PUBLIC RELEASE