Accession Number : ADA019671

Title :   Alloying Studies of Materials.

Descriptive Note : Final rept.,

Corporate Author : NORTHWESTERN UNIV EVANSTON ILL DEPT OF MATERIALS SCIENCE AND ENGINEERING

Personal Author(s) : Fine,Morris B. ; Cohen,Jerome B. ; Johnson,D. Lynn

Report Date : 30 NOV 1975

Pagination or Media Count : 22

Abstract : The fatigue crack propagation rate (da/dN) was 100 times slower in precipitation hardened aluminum-base copper alloys than in unalloyed aluminum under the same value of nominal applied load times the square root of the crack length. This difference indicates that da/dN is proportional to the reciprocal of the square of the yield stress. The results showed that the local plastic work is also important. Least-squares analysis has been carried out on integrated intensities of single crystals of vo sub x. All compositions (x) have tetrahedral V ions. Combining these results with prior electron scattering studies indicates that the state of ionization is near neutral. In zirconium oxide-zirconium specimens residual stresses due to the tetragonal to monoclinic phase transformation doubled the effective surface energy for the first crack opening made in double cantilever beam specimens. Short stainless steel fibres increased in wustite determined from bending of notched beams by a factor of 10 with 10 v/o of fibres giving the optimum results.

Descriptors :   *Aluminum, *Aluminum alloys, *Transition metal compounds, *Ceramic materials, *Defects(Materials), Composite materials, Crack propagation, Structural properties, Fatigue(Mechanics), Fracture(Mechanics), Crystal defects, Cracks, Oxides, Zirconium oxides, Zirconium, Vanadium compounds, Iron oxides, Microstructure

Subject Categories : Ceramics, Refractories and Glass
      Properties of Metals and Alloys
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE