Non-destructive evaluation of defects in structural materials using long-wavelength neutrons. Annual report No. 3, Nov 80-Dec 81

Technical Report · Fri Apr 02 00:00:00 EST 1982

OSTI ID:6794479

Fatemi, M; Rath, B B

Small-angle neutron scattering (SANS) measurements have been performed on several structural alloys to study voids and microporosities in powder consolidates of Al- and Fe-base alloys. The evolution of precipitates in Al-4%Cu and in beta-III Ti (Ti-11Mo-7Zr-5Sn-0.08Fe-.015C-0.012-0.1O) alloys subjected to varying annealing temperatures and times, and the nucleation and growth of voids formed during creep and superplastic forming in (Cu-3Al-2Si-.5Zn-0.4Co) alloys. The theta'' to theta' phase transformation in Al-4%Cu has been measured and analyzed. Calculated size density distributions show the coarsening of theta' phase with simultaneous disappearance of theta'' as a function of annealing times at 190 C. From these observations, the average size of precipitates at each stage has been calculated and compared with electron micrographic results. Similarly the precipitation of omega-phase in beta-III titanium has been observed for several annealing temperatures (600 F to 800 F) and aging times (2 min. to 100 hrs.). The observation of pronounced peaks in the small-angle profiles leads to an evaluation of the coherence length resulting from a clustering of precipitates. Microporosity in powder consolidates has been studied in two alloys: (Fe-21Cr-6Ni-9Mn-0.02C-0.25N (Wt%)) and Ti-6Al-4V. The analysis shows a variation of Guinier slopes consistent with the expectations of pore size and density variation as a function of the compaction pressure and temperature. Finally, preliminary measurements on superplastically deformed alloys of (Cu-3Al-2Si-.5Zn-.4Co) have been made under varying conditions of strain and strain rates to determine creep-induced void densities.

• Research Organization: Naval Research Lab., Washington, DC (USA)
• OSTI ID: 6794479
• Report Number(s): AD-A-113500/3
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
36 MATERIALS SCIENCE
ALUMINIUM BASE ALLOYS
MICROSTRUCTURE
COPPER BASE ALLOYS
IRON BASE ALLOYS
TITANIUM BASE ALLOYS
ANNEALING
CREEP
DEFECTS
DEFORMATION
NEUTRON DIFFRACTION
NONDESTRUCTIVE TESTING
PHASE TRANSFORMATIONS
POROSITY
SMALL ANGLE SCATTERING
STRAIN RATE
VOIDS
ALLOYS
ALUMINIUM ALLOYS
COHERENT SCATTERING
COPPER ALLOYS
CRYSTAL STRUCTURE
DIFFRACTION
HEAT TREATMENTS
IRON ALLOYS
MATERIALS TESTING
MECHANICAL PROPERTIES
SCATTERING
TESTING
TITANIUM ALLOYS
420500* - Engineering- Materials Testing
360102 - Metals & Alloys- Structure & Phase Studies