The Influence Of Process Parameters And Heat Treatment On Gamma ' Precipitates Of Selective Electron Beam Melted Ni-Based Single-Crystal Superalloy

gamma ' precipitates, the main strengthening phase of Ni-based single-crystal superalloys, are difficult to determine in the forming zone of selective electron beam melting (SEBM), which is best for realizing the direct manufacturing of single crystal superalloys. Herein, the relationship between parameters and gamma ' precipitates is urgently needed to be fabricated, and solution heat treatment is an efficient way to obtain a desired uniform gamma ' microstructure. In the initial work, an array of SEBM experiments with various processing parameters were carried out, the processing window and parameter influence on gamma ' precipitates were fabricated successfully, and a solution heat treatment protocol was applied for obtaining a homogeneous gamma ' microstructure in the as-built SEBM microstructure. In processing, the bulks can be manufactured with a beam current of 10-12.4 mA and a scan speed of 1.7-2.4 m/s. The dimensions of the gamma ' precipitates present regular changes with parameters such as current and scan speed, and a great change had also been observed in building height. After the heat treatment includes recovery-annealed (1100 degrees C, 6 h), solution-treated (1300 degrees C, 0.5 h), and aged (1100 degrees C, 6 h + 870 degrees C, 5 h) precipitates, the size of gamma ' precipitates gradually increases and homogenizes, and an optimized solution and aging heat treatment protocol was established.