LASER BENDING OF HIGH-STRENGTH ALLOYS

Laser bending has emerged as a candidate process for bending sheet met al. The dimensional accuracy of parts produced by bending processes is a topical issue, ils the dimensions of a laser bent part depend on th e temperature field induced in the workpiece, the correct laser proces sing parameters are essential. This work reports on an investigation i nto the factors influencing the dimensions of laser formed thin plates of an alpha-beta titanium and an AlCuMg aluminum alloy. The influence of the energy input on the bend angle is examined empirically and com pared with an analytical model. Results show that the plastic strain i s critically dependent on the energy supplied to the workpiece surface . The decreasing bend rate with increasing irradiations over the same track is evident. This is attributed to an increase in the sample sect ion modulus due to the thickening of the material along the bending ed ge. Edge effects are apparent in the samples. These effects can be min imized by varying the line energy supplied to the plate surface with t he in plate location. The conclusions drawn are that the dimensions of the final part and the rate of bending can be controlled primarily fr om the temperature field. In addition, the increase in the section mod ulus and the edge effects influence the dimensional accuracy. (C) 1998 Laser Institute of America.