Abstract

The single crystal superalloy with [001] orientation were prepared by screw selecting method in the directionally solidified furnace. Three different cooling method, water cooling (WC), air cooling (AC) and furnace cooling (FC) were used after same solution treatment. Then these specimens received same two-step aging treatment. Influence of solution cooling method on the microstructure and stress rupture properties of the alloy under the test condition of 980 °C and 300 MPa was investigated. The microstructures of the samples were examined by scanning electron microscope (SEM). The results showed that the solution cooling method of heat treatment played an important role in the microstructure and stress rupture properties of the alloy. The size of γ′ phase and the width of the γ matrix channel of the alloy increased with decreasing cooling rate. The stress rupture properties of the alloy increased at first and decreased afterwards with decreasing cooling rate. The alloy with air cooling (AC) has the best stress rupture properties. The γ′ phase changed into a perfect raft structure during the stress rupture process of the specimens with AC method. However, the γ′ phase changed into a very irregular raft microstructure in the specimens with the water cooling (WC) and furnace cooling (FC) method. The micro-cracks in the specimen with irregular raft make the initiation and interconnection easier than that in the specimen with regular raft. Therefore, the alloy with AC method has optimum microstructure and stress rupture property.

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.