FAULTING IN COMPACTED AG-9AT/OSN ALLOY POWDERS.
Abstract
An analysis was made of x-ray powder pattern peaks from silver-9 atomic per cent tin alloy powders compacted into briquets (1 in. diameter) with pressures up to 320 kpsi. Lattice parameter measurements indicate the presence of deformation stacking faults (probability alpha about 0.21 at the highest pressure) and small residual stresses of the order of +5 to -6 kg/sq mm (+7000 to -8500 psi). Fourier analyses of the line profiles were carried out on the (111)-(222) and (200)-(400) pairs of reflections. Pressures of 40 kpsi produce an appreciable amount of plastic deformation which is responsible for the observed effective particles sizes D sub e(111)=170A and sub e(100)=100A. Increasing the pressure to 320 kpsi, the particle sizes decrease to D sub e(111)=110A and D sub e(100)=50A. The anisotropy of the particle sizes is a consequence of the presence of microtwins and deformation faults on the (111) planes. The twin fault probability beta was separately estimated from the asymmetric (111) and (200) line profiles, and was found to increase from beta = 0.015 for 40 kpsi pressure to beta = 0.030 for 320 kpsi pressure.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1967
- Accession Number
- AD0811715
Entities
People
- Christian N. J. Wagner
- J. Hoefl
Organizations
- Yale University