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

Epitaxial CMSX-4^® deposition is achieved on CMSX-4^® 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^® deposits to the CMSX-4^® substrates. The results show that the CMSX-4^® deposits have smaller primary dendritic arm spacing, finer γ/γ′ size, weaker elemental segregation, and higher microhardness compared to the investment cast CMSX-4^® substrates. The results presented here demonstrate that CMSX-4^® 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.