About this Abstract |
Meeting |
MS&T25: Materials Science & Technology
|
Symposium
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Additive Manufacturing: Enhancement and Synergy with Traditional Methods
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Presentation Title |
Epitaxial Solidification and Cracking Behavior of CMSX-4 Welds: Assessing Additive Manufacturing Integrity |
Author(s) |
Min-Chang Shin, Eun-Joon Chun |
On-Site Speaker (Planned) |
Min-Chang Shin |
Abstract Scope |
The CMSX-4 superalloy is widely used in hot-section components such as turbine blades due to its excellent high-temperature mechanical and chemical properties. However, its poor weldability limits its use in additive manufacturing (AM) for both new fabrication and repair. This study quantitatively evaluates the brittle temperature range (BTR) of CMSX-4 using the Varestraint test with real-time thermal imaging of the melt pool to fundamentally assess AM soundness. Three linear and two oscillated gas tungsten arc welds were performed to examine epitaxial growth behavior. The BTR varied significantly (28-434 K), deviating from the conventional mushy zone concept. A strong correlation between epitaxial growth rate and BTR was observed, attributed to dendritic coalescence undercooling. Based on BTR analysis, hot crack-free and fully epitaxial welds were achieved through arc and laser welding. These experimental results were used to numerically investigate single-crystal AM feasibility. |