Numerical model of the diode laser overlapped remelting of structural steel

This paper presents a simulation of laser surface remelting with the SYSWELD finite element method software. Micro-structural changes, increase of hardness, and surface profile modification of the remelted samples are evaluated.The model input file was edited to involve laser track overlapping with a time delay. Temperature field distribution and metallographic phase proportions were extracted from output data in graphical form to demonstrate the influence of repeated melting on phase development in the overlapped region. The stored model is ready to be modified for other materials or process parameters

Characterization of titanium laser welds

Butt welding of commercially pure titanium Grade 1 and Ti6Al4V alloy sheets using a pulsed Nd:YAG laser KLS 246 - 102 LASAG were carried out to determine optimal values of pulse energy and pulse length to create completely penetrated weld. Surface peak power density of about 3.105 W.cm−2 was found as an optimal value. Weld dimensions, both face width and penetration depth, are found to be proportional to increasing energy and decreasing pulse length. Gentle sagging and root penetration were revealed by means of contact surface profilometry. The nanohardness tests on transverse cross-sections detected approximately 50% higher hardness in the fusion zone than in the base material.\