Abstract

Ceramic shell moulds for investment casting of shrouded low-pressure turbine (LPT) blades were prepared by using colloidal silica binder and partial substitution of the zircon filler with fine alumina. Among the two ceramic slurry systems designed, the first slurry system comprised of polymer-free colloidal silica binder, and the second slurry system comprised of polymer-containing colloidal silica binder. The samples prepared from the first slurry system showed higher fired residual strength and self-load sag values (lesser sag resistance). The casting of shrouded LPT blades was carried out at 1525 °C and 1550 °C using CM247LC superalloy. Ceramic shell moulds prepared from the second slurry system, containing 30 wt% of fine alumina filler, yielded aeronautical grade casting (at 1550 °C) of blades with required dimensional accuracy and average surface roughness. Microstructural analysis of the cut surfaces of self-load sag tested samples was carried out to understand the effect of fine alumina substitution on shell characteristics.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.