With the development of modern industry, the requirements for material performance are getting higher and higher, especially in the aerospace, energy power and other cutting-edge fields, the lightweight, high strength, high corrosion resistance and high temperature stability of the equipment has extremely demanding requirements. TC4 titanium alloy, with its unique physical and chemical properties, has become the ideal choice to solve these problems. However, applying titanium alloy to the casting of double-layer blade impellers is a very challenging task. The casting process of titanium alloy is prone to problems such as shrinkage holes, thermal cracking and compositional segregation, which are exacerbated by the complex structure of the double-layer blade.
This batch of casting material for high-strength titanium alloy TC4, the product's maximum rotating diameter of 427mm, the outer circle wall thickness of 9mm, blade thickness of 3mm. the batch of titanium alloy casting difficulties are:
1. the melting point of titanium alloy is relatively high, making its melting and pouring process relatively difficult.
2. titanium alloy is easy to produce porosity and other defects in the casting process, is due to titanium to oxygen, nitrogen and other impurities sensitive.
3. the coefficient of thermal expansion of titanium alloy is large, which can easily lead to shape changes and dimensional instability.
4. titanium alloy casting size is large subsequent production operation is difficult and wall thickness is easy to produce shrinkage hole.
5. the impeller is a double-layer blade, and the thickness is 3mm, the structure is complex, shell making and casting difficulties.
After many rounds of technical discussions and process tests gradually found a titanium alloy double-layer blade impeller casting key technologies. By optimizing the melting process, they effectively reduced the impurity content in titanium alloy and improved the purity and casting performance of the material. At the same time, they innovatively adopted advanced pouring system and solidification control technology, realized the smooth flow of titanium alloy melt and accurate solidification, effectively avoided the occurrence of shrinkage holes, thermal cracks and composition segregation and other problems to ensure that the impeller and the performance and stability of the internal double-layer blade.
The successful development of titanium alloy double-layer blade impeller castings is only a starting point of this journey of science and innovation. With the continuous progress of science and technology and the continuous improvement of innovation ability, titanium alloy will play a key role in more fields.
