Accession Number : ADA264297


Title :   Tensile Study of Single-Crystal Ternary L12 Trialuminide Al66Ti25Mng


Descriptive Note : Final rept. 1 Sep 91-31 Jan 93,


Corporate Author : MARTIN MARIETTA LABS BALTIMORE MD


Personal Author(s) : Brown, S A ; Kumar, K S


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a264297.pdf


Report Date : 02 Mar 1993


Pagination or Media Count : 43


Abstract : Single crystal Al66Ti25Mn9 has been produced and tested in compression as well as uniaxial tension. Yield strengths in compression for orientations near 001 and (111) continuously decrease with increasing temperature in a manner similar to other single crystal Ll 2 trialuminides, and also to polycrystals of these materials. Slip was determined to occur on the (111) octahedral planes using two-surface analysis. Critical resolved shear stress (CRSS) variation with temperature, calculated for the (111) (101) slip system, overlaps closely for both orientations. Dislocation analysis confirmed the Burgers vectors to be of the type a110 at both 298K and 1073K. A few uniaxial tension tests were conducted near (001) at 1073K; the HIPed specimens contained a small amount of residual porosity and second phases, which resulted in elastic failure even at this high temperature. Efforts to produce additional crystals with even better microstructures for tension testing are underway.


Descriptors :   *ALUMINUM COMPOUNDS , *TENSILE PROPERTIES , *SINGLE CRYSTALS , *ALUMINIDES , *MANGANESE , *TITANIUM , TEST AND EVALUATION , COMPRESSION , TEMPERATURE , ELASTIC PROPERTIES , PHASE , SURFACES , AXIAL FLOW , TERNARY COMPOUNDS , YIELD STRENGTH , OVERLAP , TENSION , SHEAR STRESSES , RESIDUALS , DISLOCATIONS , VARIATIONS , POROSITY , FAILURE , HIGH TEMPERATURE , MATERIALS , SURFACE ANALYSIS , MICROSTRUCTURE


Subject Categories : Inorganic Chemistry
      Properties of Metals and Alloys
      Crystallography
      Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE