THE EFFECT OF FABRICATION HISTORY AND MICROSTRUCTURE ON THE MECHANICAL PROPERTIES OF REFRACTORY METALS AND ALLOYS

Technical Report · Wed Jul 10 04:00:00 EDT 1963

OSTI ID:4096763

Imgram, A G; Ogden, H R

The relationships between fabrication history, microstructure, and the mechanical properties of refractory metals and alloys depend on factors such as grain size and shape, second-phase distribution, and impurity content and location. The characteristic behavior of alloys strengthened by dispersions differs from that for alloys strengthened by solid-solution alloying. Dispersionforming alloy additions increase strength and resistance to recrystallization. Furthermore, their grain-refining effect generally results in a lowering of the ductile-tobrittle transition temperature. Solution-annealing and aging heat treatments can often refine the dispersion distribution and lead to greatly improved strength. This ability to alter the dispersion distribution makes this type of ailoy quite sensitive to fabrication history. Solidsolution alloying additions also increase the strength and resistance to recrystallization. Although the strengthening effects of solid-solution additions can be retained to much higher temperatures than is generally the case with dispersion additions, they usually impair the ductility. Large working reductions considerably increase the strength and lower the ductile-to-brittle transition temperature. Both dispersion and solid-solution-strengthening additions increase work- hardening rates. Interstitial impurities can greatly increase the ductile-to- brittle transition temperature of unalloyed refractory metals and of solid- solution-strengthened alloys and are not greatly beneficial to strength and resistance to recrystallization. An interstitial content close to the stoichiometric ratio with compound-forming reactive-metal additions is necessary to realize the foil strengthening potential. (auth)

• Research Organization: Battelle Memorial Inst. Defense Metals Information Center, Columbus, Ohio
• NSA Number: NSA-18-008717
• OSTI ID: 4096763
• Report Number(s): DMIC-186; AD-423952
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ALLOYS
ANNEALING
BRITTLENESS
CONFIGURATION
DEFECTS
DISTRIBUTION
DUCTILITY
FABRICATION
GRAIN SIZE
HEAT TREATMENTS
IMPURITIES
INTERSTITIALS
LATTICES
MECHANICAL PROPERTIES
METALS
METALS, CERAMICS, AND OTHER MATERIALS
PHASE DIAGRAMS
QUANTITY RATIO
RECRYSTALLIZATION
REFINING
REFRACTORIES
SOLID SOLUTIONS
SOLUTIONS
TENSILE PROPERTIES