Application status and prospect of titanium alloy casting core

When forming titanium alloy castings with complex internal cavity structure, the correct selection and use of core is very important. Three kinds of cores (graphite core, metal core, ceramic core) which are widely used in titanium alloy casting are systematically described, and the future development of cores is prospected, in order to provide useful reference for the improvement of the manufacturing level of high-end titanium alloy parts in China.

Because of its excellent comprehensive properties, such as low density, high specific strength, high temperature resistance and corrosion resistance, titanium alloy has become an indispensable advanced structural material in modern industry. Especially in recent decades, with the rapid development of the space industry and the defense industry, the use and application level of titanium alloys have been improved. However, with the continuous innovation and development of aviation and aerospace technology, the service environment of key components has become increasingly harsh, which not only directly leads to the complexity of titanium alloy component structure, but also puts forward higher requirements for the casting level of titanium alloy. Taking a titanium alloy engine component as an example (FIG. 1), its overall size is about Φ300 mm×150 mm, with multiple cavities, complex structure and high profile quality requirements. At this time, only relying on the shell can not meet the casting needs of the casting, and it must be achieved by cooperating with the core and the shell. It can be seen that the preparation of the core has become an indispensable prerequisite for casting titanium alloy castings with complex cavity. The successful preparation and application of the original simple core such as hollow steel pipe to the existing complex flow channel, hollow blade and other heterotropic core lay the foundation for titanium alloy casting.