Direct laser deposition of crack-free CM247LC thin walls: Mechanical properties and microstructural effects of heat treatment

Abstract

CM247LC is classified as a non-weldable Ni alloy due to the high Ti + Al content, which makes it susceptible to cracking. It is particularly prone to microcracking when processed by direct laser deposition (DLD). In this work, multiple single walls were manufactured by DLD in CM247LC using two different laser modes: continuous wave and pulse wave (PW). The manufactured walls were studied during processing and post-processing, and characterised by scanning electron microscopy, electron backscattered diffraction, thermal analysis and X-ray diffraction. The results indicate that crack-free conditions during the deposition process and the subsequent thermal processing can be achieved using the PW laser mode and that this can also lead to outstanding mechanical properties.