Phase and microstructural evolution of BaZrO₃‐CaZrO₃ refractory and its interaction with titanium alloy melt

Abstract

In this study, the effect of CaZrO3 additives on the phase and microstructure of BaZrO3 refractory were investigated as well as the interaction with titanium alloy melts. Results revealed that no second phase was observed in the BaZrO3 refractory with 10 and 20 mol% CaZrO3 additives, respectively, and the incorporation CaZrO3 additives promoted the densification and the growth of grains due to the generation of BaZrO3‐CaZrO3 solid solutions. Whereas, the appearance of CaZrO3 phase was in the BaZrO3 refractory with 30 mol% additive, indicating that the additive content excessed the solid solubility limit in the BaZrO3 refractory. Interaction analysis indicated that CaZrO3 additive could improve the performance of BaZrO3 refractory for resisting the penetration of Ti2Ni alloy melt. Meanwhile, an increasing extent of melt contamination by the BaZrO3 refractory was also detected with the increasing content of CaZrO3 additive. According to the thermodynamic calculation, an obvious increase in Gibbs free energy of formation for the BaZrO3 refractory was confirmed with the CaZrO3 additive, resulting in the increasing extent of the dissolution‐corrosion between the refractory and the titanium alloy melts.

Role of Ca additive on the effect of phase composition and microstructure of BaZrO3 refractory and its interaction with titanium alloys

“…In our previous study it was noted that CaZrO 3 was undergoed a limited solid solution reaction with BaZrO 3 . 21 Thus, both the CaZrO 3 and Ba 1-x CaxZrO 3 phases were present in the B3 crucible, due to the excess of CaZrO 3 . According to Equations 1 and 2, the absence of the Ba 1-x Ca x ZrO 3 phase in the B1 and B2 crucible might be attributed to the low precursor CaO content, which caused the less CaZrO 3 to be involved in the reaction to obtain less Ba 1-x Ca x ZrO 3 phase.…”

Problems of Materials Choice for Ceramic Molds to Obtain Titanium Alloys Shape Castings

“…Цирконат барію BaZrO 3 хоч і показує гарну інертність до титанових розплавів, але має незадовільні технологічні властивості, тому може використовуватися лише з добавками інших вогнетривів. В [23] спробували поліпшити характеристики вогнетриву BaZrO 3 шляхом додавання CaZrO 3 . При цьому введення добавок CaZrO 3 у кількості 10 і 20 мол.% сприяло ущільненню та росту зерен завдяки утворенню твердих розчинів BaZrO 3 -CaZrO 3 .…”

Influence of sintering temperature on the interfacial behavior of Ti3Al(Si)C2 ceramic and Ti6Al4V alloy

“…[39][40][41][42][43][44] For Ti 3 AlC 2 materials, it was reported that an appropriate amount of assistants (such as Si, Sn, and Nb) played a positive role in improving the purity and enhanced properties (hardness, strength, oxidation resistance, etc.). [45][46][47][48][49][50][51][52][53] For example, Ai et al 45 pointed out that the addition of Sn could extend the range of synthesis temperature and inhibit the forming of TiC and other impurities in the synthesis process of Ti 3 AlC 2 ceramic by preventing the generation of thermal explosion. Huang et al 46 reported that flexural strengths of Ti 3 Al 0.8 Sn 0.2 C 2 and Ti 3 Al 0.6 Sn 0.4 C 2 solid solution improved when compared with pure Ti 3 AlC 2 , which was a result of solid solution strengthening.…”

“…The interaction would lead to a hardened generated layer on the metal surface, thereby affecting the performance of the metal. According to the chemical inertness of ceramics, many researchers [52][53][54][55][56][57][58][59] investigated the interaction between Tibased alloy with BaZrO 3 , CaZrO 3 , CaO, and so on. In addition, Cheng et al 60 proposed TiAlO-based refractories, a system containing Ti and Al, for the investment casting of titanium alloys.…”

“…For Ti 3 AlC 2 materials, it was reported that an appropriate amount of assistants (such as Si, Sn, and Nb) played a positive role in improving the purity and enhanced properties (hardness, strength, oxidation resistance, etc.) 45–53 . For example, Ai et al 45 .…”