High Temperature Deformation of Polycrystalline β-Alumina

Grain Boundaries in Polycrystalline Alumina

Deformation and Grain Growth of Low-Temperature-Sintered High-Purity Alumina

9 = 0.6 I / s ' 7 = 6.0 0 7 = 2 4 i ti 3 = 6 0 Through close control over green-state powder processing, pure alumina ceramics of 0.5-pm grain size were obtained by sintering at 1250°C. The static grain growth of this material was modest at temperatures below 1300°C. However, dynamic grain growth occurred rapidly during superplastic deformation. Therefore, although the ultrafine-grained alumina...

Localization of deformation in polycrystalline ice

Since ice deforms mainly by dislocation glide on the basal planes, very strong incompatibilities exist between the grains of a polycrystal. Specially designed two-dimensional compression creep tests on different types of ice multicrystals embedded in a matrix of fine-grained isotropic ice allow to observe the strain heterogeneities which arise during the deformation of polycrystalline ice, and ...

High-strain-rate Deformation of Pure Aluminum Reinforced with 25% Alumina Submicron Particles near the Solidus Temperature

Discontinuously reinforced aluminum metal matrix composites (MMCs) with about 20 vol.% reinforcement produced by powder metallurgy (PM) are attractive for many structural applications because of their high specific strength and stiffness. While they exhibit reduced ductility and toughness at room temperature, many of them can be superplastically deformed at high-strain rates in the vicinity of ...

Effect of liquid-forming additives on low-temperature superplastic deformation of alumina

It has recently been reported that in the Y203-stabilized tetragonal zirconia phase (TZP) system the addition of a small amount of transition-metal oxides (e.g. CuO, MnO and ZnO) which form a liquid or amorphous grain boundary phase significantly enhances superplasticity [1, 2]. In CuO-added 2Y-TZP abrupt changes have been found in the stress exponent and activation energy across the melting te...