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 distribution of cavity sizes in a microduplex α/β copper-zinc-nickel-manganese alloy (a nickel-silver) subjected to superplastic tensile straining has been examined as a function of strain, temperature and strain rate using quantitative optical metallography. The number of cavities that became optically visible increased throughout straining, but the rate at which they became visible decreased at higher strains. The distributions of cavity sizes in specimens deformed to the same strain at different temperatures or strain rates were essentially identical. The size distribution data were fully consistent with the observations that for a given strain the overall volume of cavities formed in the alloy was independent of temperature and strain rate. Growth for all cavity sizes is dominated by matrix plastic flow. The insensitivity of void volume and cavity size distribution to strain rate and temperature, and hence stress, reflects the resolution of the density and metallographic techniques. While higher stresses will lead to a wider range of initial cavity sizes by lowering the critical nucleus size, cavities at the lower end of the size range will not grow sufficiently to become optically resolvable or to produce a density differential compared with a specimen deformed to the same extent at a lower stress.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01120044
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