Effect of Line Energy Density on Microstructure and Tensile Properties of Cobalt-based Alloy by Laser Direct Metal Deposition

摘要

Direct Laser Metal Deposition (DMD) processes can be utilized to generate functional parts providing an opportunity to generate complex shaped or functionally graded. In this paper, the relationship between energy density and microstructure of cobalt base alloy during DMD process has been discussed mainly. The microstructure, properties and preparation mechanisms of the specimens were studied using metallographic microscopy, scanning electron microscopy and X-ray diffraction. The result shows that relative density of the deposited builds is more than 99.40%. With the decrease of energy density, the relative density is reduced, the grain size and secondary dendritic space are also decrease. The average tensile strength and yield strength is 860.27 MPa and 572.4 MPa, respectively. The average elongation is 19.97%. The deposited specimens show obviously anisotropy at tensile property due to columnar grain microstructure throughout interlayer.