Microstructures and Microhardness Properties of CMSX-4A® Additively Fabricated Through Scanning Laser Epitaxy (SLE)

Epitaxial CMSX-4(A (R)) deposition is achieved on CMSX-4(A (R)) substrates through the scanning laser epitaxy (SLE) process. A thorough analysis is performed using various advanced material characterization techniques, namely high-resolution optical microscopy, scanning electron microscopy, energy-dispersive x-ray spectroscopy, x-ray diffraction, and Vickers microhardness measurements, to characterize and compare the quality of the SLE-fabricated CMSX-4(A (R)) deposits to the CMSX-4(A (R)) substrates. The results show that the CMSX-4(A (R)) deposits have smaller primary dendritic arm spacing, finer gamma/gamma' size, weaker elemental segregation, and higher microhardness compared to the investment cast CMSX-4(A (R)) substrates. The results presented here demonstrate that CMSX-4(A (R)) is an attractive material for laser-based AM processing and, therefore, can be used in the fabrication of gas turbine hot-section components through AM processing.