Methods for preparing prefabricated crack defect and built-in crack defect, and prefabricated member

Abstract

A method for preparing the prefabricated crack defects includes defining a defect area, defining a volume percentage of the crack defects in the defect area, adjusting the proportion of spherical powder, the proportion of hollow powder and process parameters of defect preparation according to the volume percentage of the crack defects, based on the technique of laser melting deposition, printing the defect area layer by layer by using the defect preparation powder and the process parameters of defect preparation, wherein the particle size of the defect preparation powder is between 45 μm and 150 μm, the proportion of spherical powder≥93% and the proportion of hollow powder<0.5%, the process parameters of defect preparation including: laser power of 450W-550W, scanning rate of 600 mm/min-1200 mm/min, powder feeding rate of 4 g/min-12 g/min, spot diameter of 1 mm-1.2 mm, scanning spacing of 0.5 mm-0.8 mm and layer thickness of 0.08 mm-0.2 mm.