An investigation of ceramic shell thickness uniformity and its impact on precision in turbine blade investment casting

Investment casting plays a pivotal role in the fabrication of complex and precise components, notably turbine blades for aerospace and energy industries. During the casting process, the non-uniform shell thickness distribution affects the dimensional accuracy and surface quality, and further impact the performance and reliability of the products. This study delves into the effects of turbine blade casting system design, focusing on shell thickness uniformity and its correlation with casting dimensional accuracy. Through an experimental setup that manipulates wax pattern attitude angles and module diameters, coupled with the Industrial Computed Tomography (ICT) for non-destructive thickness measurement, this study uncovers the critical role of centrifugal effects during the slurry application in modulating shell thickness uniformity. Our findings reveal that strategic adjustments to the wax pattern attitude angle and module diameter can significantly enhance shell thickness uniformity, thereby potentially increasing the structural integrity and dimensional precision of turbine blades. In addition, a positive correlation between shell inhomogeneity and casting manufacturing deviation was found through casting profile inspection and correlation analysis. This research not only elucidates the relationship between manufacturing parameters and shell formation but also proposes practical adjustments to the casting system design, offering new pathways to refine investment casting processes for high-value components.