Experimental Investigation and Thermodynamic Modeling of the ZrO2-MgO System
Experimental Investigation and Thermodynamic Modeling of the ZrO2-MgO System
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DOI：
10.1002/adem.201200316
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发表时间：
2013-07-01
影响因子：
3.6
通讯作者：
Fabrichnaya, Olga
中科院分区：
文献类型：
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作者：
Pavlyuchkov, Dmytro;Savinykh, Galina;Fabrichnaya, Olga
氧化锆陶瓷是一种非常有工业价值的著名材料。然而，在纯ZrO2中，冷却时会发生不希望发生的自发相变。添加氧化物稳定剂Y_2O_3、CaO、MgO等可以在室温下获得具有四方和立方(萤石)结构的ZrO_2基固溶体。稳定的状态为陶瓷提供了更好的性能。将稳定化的氧化锆与其他材料相结合，可显著改善其力学性能。应力或温度辅助下的马氏体相从四方相向单斜相的转变伴随着高剪切和体积膨胀。由于这一特性，最近有人建议将部分稳定的氧化镁(Mg-PSZ)作为TRIP钢的增强成分。[1]镁-PSZ颗粒的体积膨胀增强了钢的TRIP效应。由于形变诱发马氏体的形成，TRIP效应导致高应变硬化和高塑性。有关包括稳定组分在内的ZrO2基陶瓷系统的相平衡的信息是非常重要的。该相图可以用来解释TRIP基复合材料的相变和观察到的微观结构。此外，相图还有助于优化陶瓷的化学成分和热处理工艺。此外，通过包括工业材料中的杂质，即Al_2O_3和SiO_2以及来自钢的铁氧化物和其他氧化物来模拟陶瓷材料和钢/陶瓷界面上的过程，可以进一步扩展ZrO_2-MgO关键体系。在TRIP基复合材料的陶瓷组分热力学数据库的开发中，对再现相平衡的热力学参数的评估起着至关重要的作用。
ZrO2 ceramics is a well known material of great industrial interest. However, the undesirable spontaneous phase transformations occur on cooling in pure ZrO2. Additions of oxides-stabilizers such as Y2O3, CaO, MgO, etc. allow us to obtain ZrO2-based solid solutions with the tetragonal and cubic (fluorite) structures at room temperatures. The stabilized states provide the ZrO2 ceramics with improved properties. Combination of stabilized ZrO2 with other materials may significantly improve their mechanical characteristics. The stress or temperature assisted martensite transformation from the tetragonal to the monoclinic modification of the ZrO2 phase is accompanied by a high shear and volume expansion. Due to this behavior the MgO partially stabilized zirconia (Mg-PSZ) was recently suggested as a reinforced component for TRIP steel.[1] The volume expansion of the Mg-PSZ particles enhances the TRIP effect of the steel matrix. The TRIP effect leads to high strain hardening and high ductility due to the deformation-induced formation of martensite.The information about phase equilibria in the ZrO2 based ceramic systems including stabilized components is of great importance. The phase diagram of the ZrO2–MgO system can be used to explain phase transitions and observed microstructure in the TRIP-matrix composite. Additionally the phase diagram can also help to optimize the chemical compositions and heat treatment procedures of the ceramics. Furthermore, the ZrO2–MgO key system can be further extended by including impurities of industrial material, ie Al2O3 and SiO2 as well as iron oxides and other oxides originating from steel to model the processes in the ceramic material and at the steel/ceramic interface. An assessment of thermodynamic parameters reproducing phase equilibria occurring in the ZrO2–MgO system plays a crucial role in the development of thermodynamic database for ceramic constituent of the TRIP-matrix composite.