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Indexed by:会议论文

Date of Publication:2011-11-04

Included Journals:EI、CPCI-S、Scopus

Volume:512-515

Page Number:407-+

Key Words:Oxide ceramic composite; Superplastic forming; Mechanical properties

Abstract:The paper mainly focused on the two issues that restricted the practical application of superplastic ceramics, which were the low strain rate in superplastic forming as well as resulted severely cavitation in deformed materials. The alumina-based composites Al2O3-ZrO2(3Y) and Al2O3-30mol%ZrO2(3Y)-30mol%MgAl2O4 (AZ30S30) were selected as research materials. The nano-sized composite powders were synthesized by heating of ethanol-aqueous salt solution method. The superplastic forming tests under the compressive stress state were carried out to evaluate the superplastic formability of the as-sintered materials. The results demonstrated that the following conditions were the essentials for attaining high-strain-rate superplastic forming in alumina based ceramic composites: reduced the initial grain size and suppressed dynamic grain growth in deformation by second phase dispersion, enhanced diffusivity by co-doped certain elements, as well as provided new rate-controlling accommodation process in superplastic forming. The results also indicated that during the superplastic forming the cavitation damage was eliminated because of the compression stress state, which ensured the mechanical properties after deformation.