Erscheint 4 Ausgaben pro Jahr
ISSN Druckformat: 1093-3611
ISSN Online: 1940-4360
Indexed in
PREDICTION OF THERMAL HISTORY IN LASER METAL DEPOSITION
ABSTRAKT
The mechanical behavior of the part produced by laser metal deposition (LMD) depending on the thermal history-based microstructure (resulting anisotropic properties) is not fully understood at present. A numerical model that is adequate for predicting thermal history, including melt pool size, thermomechanical residual stress distribution, temperature profile for single layer, multilayer having different track and real-time material addition during laser metal deposition process has been developed in the present study. In addition, the effect of surface tension on the droplet shape with and without solidification is also predicted by the developed numerical model. The simulated and measured thermal history indicated that the absorption and loss of heat tended to be close to equilibrium when the deposited material reached a certain height (found in simulation) during the LMD process. The melt pool length increases from 1.6 mm at the 1st layer to 3.2 mm at the 17th layer. The stress was measured at the base of the deposited part; it was found that the peak of the stress goes up to 1800 MPa during simulation at the corners of the deposited part and at the end of simulation it decreases to 320 MPa. Then it was cooled to room temperature, and residual stress was found to be equal to 175 MPa.