Superplasticity in 3Y-TZP doped with small amounts of copper oxide
- Pennsylvania State Univ., University Park, PA (United States). Dept. of Materials Science and Engineering
Yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) can be deformed superplastically in tension to over 100% strain, and many studies have been undertaken to characterize this superplastic behavior. One drawback of high purity Y-TZP is that the temperature needed in order to achieve practical superplastic forming stresses and strain rates can be prohibitive. However, the addition of a glassy or amorphous phase to Y-TZP grain boundaries has been shown to increase strain rates for a given stress. These grain boundary phases an form either through the segregation of impurities such as silica to grain boundaries, or through the intentional addition of sintering aids such as transition metal oxides. Studies have shown that strain rates of Y-TZP can be accelerated by up to two orders of magnitude through the addition of only 0.3 mol% CuO. It is believed that the CuO helps to form an amorphous grain boundary phase which is molten at typical forming temperatures, providing a fast diffusion path during deformation which occurs via a grain boundary sliding mechanism. Grain boundary sliding, in turn, may be controlled either by diffusion along grain boundaries or by the attachment/detachment of atoms at the interface between the grain boundary and the bulk grains. When grain boundary diffusion is fast, as is believed to be the case in CuO-doped Y-TZP, The interface reaction will be the controlling mechanism. Assuming that a glassy or amorphous phase exists uniformly along grain boundaries, the strain rates associated with interface reaction controlled grain boundary sliding should not be a function of the amount of grain boundary phase, since the area of the interface will remain approximately the same for different amounts of phase. The purpose of the present study is to examine the effect of small amounts of CuO dopant on Y-TZP in order to determine the dependence of strain rate on the amount of grain boundary phase within this regime.
- OSTI ID:
- 7154356
- Journal Information:
- Scripta Metallurgica et Materialia; (United States), Journal Name: Scripta Metallurgica et Materialia; (United States) Vol. 31:12; ISSN SCRMEX; ISSN 0956-716X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effect of grain size on superplastic behavior of Y-TZP
Microstructural examination of a superplastic yttria-stabilized zirconia: Implications for the superplasticity mechanism
Related Subjects
360203* -- Ceramics
Cermets
& Refractories-- Mechanical Properties
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
DATA
DEFORMATION
DOPED MATERIALS
EXPERIMENTAL DATA
INFORMATION
MATERIALS
MECHANICAL PROPERTIES
METALLURGICAL EFFECTS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PLASTICITY
STRAIN RATE
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES