Impurity Atom-Dislocation Interactions and Subsequent Effects on Mechanical Properties of Refractory Metals

Item

Title
Impurity Atom-Dislocation Interactions and Subsequent Effects on Mechanical Properties of Refractory Metals
Date
1962
Index Abstract
Coming Soon
Photo Quality
Not Needed
Report Number
ASD TDR 62-11
Creator
Adams, M. A.
Nesor, H.
Corporate Author
Materials Research Corporation
Laboratory
Directorate of Materials and Processes
Extent
30
Identifier
AD0276195
Access Rights
OTS
Distribution Classification
1
Contract
AF 33(616)-7596
DoD Project
7351 - Metallic Materials
DoD Task
735101
DTIC Record Exists
No
Distribution Change Authority Correspondence
None
Abstract
Studies were made of (1) the strain-aging behaviour and (2) the effect of pre-straining and high temperature annealing of Mo crystals of two different purity levels prepared by electron beam melting. One batch of crystals contained an average of 20 ppm total interstitial impurities, the other an average of 250 ppm interstitials with the major constituent being carbon. Yield point experiments revealed no strain-aging in either material in the ''as-grown'' condition, but after a high temperature anneal followed by rapid cooling the material containing C showed appreciable aging effects, and the purer material weak effects. The results are explained in terms of the low solid solubility of the interstitial elements in Mo under equilibrium conditions at moderate temperatures. The second series of experiments showed that pre-straining and annealing treatments which produce a substructure in Mo, also result in a strengthening of the material. The strengthening increases with increasing pre-strain and with increasing C content. The results indicate that sub-grain boundaries strengthen Mo in a qualitatively similar way to ordinary grain boundaries.
Report Availability
Full text available
Date Issued
1962-03
Provenance
Lockheed Martin Missiles & Fire Control
Type
report
Format
1 online resource