Accession Number : AD0428334


Title :   THE EFFECT OF SOLUTE-IMPERFECTION INTERACTIONS UPON PLASTICITY AND FRACTURE.


Descriptive Note : Final rept., 1 Nov 60-31 Oct 63,


Corporate Author : NORTHWESTERN UNIV EVANSTON ILL


Personal Author(s) : Brittain,J O


Report Date : 31 Oct 1963


Pagination or Media Count : 12


Abstract : This reort is concerned with an investigation of the effect of solute-imperfection interactions upon plasticity and fracture. Insofar as the yielding of materials that deform in a heterogeneous manner are concerned, we have demonstrated that the addition of a hard noncoherent particle such as aluminum oxide to alpha-iron results in a modification of the yielding, flow, and strain aging of the alpha-iron. The hard particles appear to act as dislocation sources and to effect the velocity of dislocations in the alpha-iron matrix. From these results, it is suggested that the aluminum additions made in the production of ''killed'' steel has two roles: (1) the well known chemical effect of decreasing the nitrogen content by the formation of a nitride and (2) from our work a physical effect probably due to the trapping of interstitial elements at dislocations associated with the inclusions formed in the deoxidation and denitriding practice. An experimental investigation of the influence of departure from stoichiometry upon plasticity in NiAl revealed that the compressive yield stresses were in general higher for the substitutional defects (high Ni composition) than for the vacancies (low Ni compositions). (Author)


Descriptors :   *SOLUTIONS(MIXTURES) , PLASTIC PROPERTIES , FRACTURE(MECHANICS) , ALUMINUM COMPOUNDS , OXIDES , IRON , PARTICLES , VELOCITY , STEEL , NITROGEN , NITRIDES , NICKEL ALLOYS , ALUMINUM ALLOYS , HIGH TEMPERATURE , SCIENTIFIC RESEARCH


Distribution Statement : APPROVED FOR PUBLIC RELEASE