Influence of Parameters on Macro/micro-structure of TC11 Alloy by Laser Direct Deposition

Understanding the effect of process parameters on microstructure is crucial to control or optimize microstructure for laser direct deposition process. Four thin-wall samples of TC11 titanium alloy are deposited with different process parameters. They showed different macro/micro-structure and mechanical properties. The reason is analyzed by temperature field of samples which are simulated by ANSYS software. Results show that, deposition with low laser power and slow scanning speed is conducive to reducing molten pool temperature and soaking time in beta-phase region, refining original beta grain and improving the plastic properties of the deposited parts. Deposition with high laser power and rapid scanning speed, combined with interlayer stay, is helpful to increase the cooling rate within alpha+beta phase region, refine intragranular alpha lamellar and improve the tensile strength of deposited parts.