The forming of mild steel plates with a 2.5 kW high power diode laser

Abstract

Bending of 07 M20 mild steel sheets to various degrees using a contemporary 2.5 kW high power diode laser (HPDL) has been successfully demonstrated for the first time. The experimental results revealed that the HPDL induced bending angle increased with an increasing number of irradiations and high laser powers, yet decreased as the traverse speed was increased. It was also apparent from the experimental results that the laser bending angle was only linearly proportional to the number of irradiations when the latter was small. It is believed that the absence of linearity observed when the number of irradiations was high is due to local material thickening along the bend edge. From graphical results and the employment of an analytical model, the laser line energy range in which accurate control of the HPDL bending of the 07 M20 mild steel sheets could be exercised was found to be between 138 J mm -1 and 260 J mm -1 .

Controlling thermal deformation using a heat sink in laser transformation hardening of steel sheets

“…In other words, with a heat sink, it is as though the effective heat input is decreased, which results in a decrease in the deformation angle. As reported in literature (Lawrence et al, 2001), plastic deformation angle is proportional to the amount of heat input.…”

Numerical investigation on laser-produced microstructure of metal under non-melting condition

“…Under the temperature gradient mechanism [8][9][10][11], a fast scan of the laser beam over the sample forms a steep thermal gradient across the thickness that produces differential thermal expansion. Compressive stresses arise because of the thermal expansion of the heated area.…”

Modification of bent angle of mechanically formed stainless steel sheets by laser forming

“…F > 1. As highlighted by Lawrence et al (2001) laser spot diameter should be of the order of sheet thickness to realise temperature gradient mechanism and upsetting mechanism, whereas it should be much larger than sheet thickness for buckling mechanism to occur. In laser forming of 0.8 mm thick 07 M20 steel sheets using high power diode laser they observed 0.1 • -3 • bending angle per pass using temperature gradient mechanism.…”