ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The tensile behaviour of mechanically alloyed (dispersion strengthened) IN90211 was characterized at strain rates between 0.0001 and 340 sec−1 at temperatures between 425 and 475 ° C, At strain rates above 0.1 sec−1, superplastic elongations were obtained (maximum elongation 525% at 475 ° C, 2.5sec−1. Large elongations were possible due to the lack of cavitation, even though the strain-rate sensitivity was lower (m ≈ 0.25) than usually found in superplasticity. Cavitation was precluded by the morphology of the platelet-shaped grains in which low-angle subgrain boundaries were predominantly perpendicular to the tensile axis. Grain-boundary sliding was observed along high-angle grain boundaries which were generally parallel to the tensile axis. At the high homologous testing temperatures (0.76 to 0.81), concurrent grain-boundary sliding and lattice slip was made possible by the rapid lattice diffusivity and easy climb of lattice dislocations over dispersions in the matrix and grain boundaries.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00582492
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