A Novel Concurrent Preheating Additive Manufacturing Process Using Dual-Electron Guns to Inhibit Hot Cracking in Non-Weldable Nickel-Based Superalloys

The Electron Beam Powder Bed Melting (EB-PBF) process has been recognized for its effectiveness in preparing non weldable nickel based high-temperature alloys, utilizing high-temperature preheating to minimize stress-related issues. Traditionally, the EB-PBF process involves pausing preheating scanning during the printing stage when only one electron gun is available, which can cause significant temperature fluctuations and hot cracks in these alloys during solidification. In order to address the challenges of manufacturing complex parts using such materials, a new synchronous preheating electron beam powder bed melting (CPEB-PBF) process using dual electron guns has been introduced. This innovative method synchronizes preheating and printing scanning, stabilizing the manufacturing temperature above 1100 ° C and significantly suppressing thermal cracks in complex components. In addition, the microstructure, properties, and mechanisms behind reducing crack formation were explored, emphasizing the critical role of continuous temperature control in enhancing the integrity and performance of manufacturing materials. The CPEB-PBF process has become a promising solution for manufacturing materials that are difficult to process, paving the way for wider applications in advanced engineering fields.