Superplasticity and superplastic-like flow in cubic zirconia with silica
2015
Shirooyeh, Mahmood | Dillon, R Peter | Sosa, Siari S. | Imamura, Phil H. | Mecartney, Martha L. | Langdon, Terence G.
Experiments were conducted at temperatures from 1573 to 1748 K to evaluate the flow properties and the potential for achieving superplasticity in an 8 mol% Y₂O₃-stabilized cubic ZrO₂(termed 8Y-CSZ) containing 5 wt% colloidal SiO₂. Tests were conducted under constant strain rate conditions and under creep conditions at constant stress. The stress exponent was determined as ~1.8, and the activation energy for creep was measured as ~600–670 kJ mol⁻¹. The results show that the presence of an amorphous second phase is effective in limiting grain growth. A maximum superplastic elongation of more than 500 % was recorded at a testing temperature of 1703 K. An analysis of the results suggests that the flow mechanism is associated with interface-controlled diffusion creep.
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