Study On Laser Bending For Metal Sheets And Mechanism

Laser bending of sheet metal is a flexible forming technology. Its mechanism is that the plastic deformation caused by thermal stresses induced by irradiation of high power laser beam scanning. Laser bending has some features such as no external forces and no hard dies, high producing flexible, low producing prices, short producing cycle and high forming precision, and even brittle materials can be deformed. Moreover, laser forming can be combined with other conventional laser beam technology for producing prototypes and functional models.The characteristics of laser bending, for a super-thin stainless steel sheet and a middle-thin low carbon steel sheet, were investigated respectively by means of different experimental methods. The influences of laser power, laser scanning alternation, geometrical dimension, and so on, upon laser bending procedure were analyzed. The results showed that the influence of laser power, number of scans, and width of metal sheet was positivegoing; while the influences of traverse speed, beam dimension and thickness of metal sheet was negativegoing.The microstructure and microhardness test for laser bending samples were analyzed. The results showed that the ferrite structure refined, the quantities of pearlite increased, and few of carbides were precipitated for some parameters. So the performance of the samples would be improved primely.The deepen investigation of laser reverse-bending for metal sheet was conducted by using of the orthogonal experimental design. The microstructures of laser reverse-bending samples were analyzed. The mechanism of laser reverse-bending was discussed and the stress model of it was brought forward. The key factors on laser reverse-bending procedure were found as: beam dimension and traverse speed; and the latter being more important. All these theorys had been testified through some experiments.The samples were produced with relative optimal experimental parameters.