Проблеми вибору матеріалів керамічних форм для одержання фасонних виливків із титанових сплавів: Processy litʹâ, 2021, Tom 146, №4, p.55-65

• Date: 2021
• Main Authors: Калюжний, П. Б., Михнян, О. В., Ворон, М. М., Тимошенко, А. М., Нейма, О. В.
• Format: Article
• Language: Ukrainian
• Published: National Academy of Sciences of Ukraine, Physical-Technological Institute of Metals and Alloys of NAS of Ukraine 2021
• Subjects: титанове литво; лиття в одноразові керамічні форми; взаємодія розплаву та форми
• Online Access: https://plit-periodical.org.ua/index.php/plit/article/view/83
• Journal Title: Casting Processes

Received 09.11.2021 UDK 621.74.045 The production of precision small or single-set titanium casting is economically and technologically feasible by providing investment casting in ceramic molds. It is extremely important to choose the material of the mold inner contact layer and to ensure the specified technological characteristics - roughness, strength, etc. In the course of presented analysis, it is shown that among ceramic refractories, the best inertness to the action of liquid titanium alloys is shown by yttrium oxide, calcium and barium zirconates. But, due to low technological properties, such coatings have not been widely used. It is also shown that binders also significantly affect the inertness of ceramic molds. Reducing the interaction of titanium with ceramic molds that contain silica as a binder can be achieved by introducing a minimum amount of SiO2 . From an ecological point of view, instead of ethyl silicates, it is better to use aqueous solutions of silica. Promising binders are also aluminosols and zirconium sols. It is determined, that increasing the inertness of corundum molds can be achieved by modifying them with dops of fine titanium powder, which forms a protective layer on the surface of the molds during sintering, that reduces an interaction of liquid metal with the ceramic mold. It is noted that the mechanism of the reaction (alpha) layer formation on the surface of titanium castings is still not precisely defined. Interfacial reactions between titanium and ceramic mold can not be predicted only by thermodynamic calculation, but also must take into account the wetting factors of materials, the chemical composition of the alloy, the kinetics of dissolution and evaporation of refractory oxides.