In order to evaluate the microstructure and performance of large-scale complex titanium alloy castings and other aircraft critical structural components

the structural uniformity of a titanium alloy mainframe casting was analyzed. By analyzing the distribution of the various regions of the casting and the presence of anomalous grains

the key factors affecting the casting microstructure were described

and the microstructure homogeneity of a titanium alloy mainframe casting was evaluated. The results show that the grain size in the castings is in range of 44 μm to 7 660 μm

and the sizes of 82% of the grains are within 1 650 μm. As the thickness of the casting increases

the average grain size and the FWHM of the surface layer and the center layer of the casting show a nearly logarithmic increased trend. The factors such as wall thickness

structural characteristics and pouring sequence of the castings all have an important influence on solidification

of which the wall thickness has the most significant effect.