Probing the Role of Temperature-Dependent Material Property Profiles During Laser Forming Via Finite Element Analysis

Material properties have often only been considered in analyses of laser sheet metal forming in the manner that they contribute to the bulk operating-temperature mechanical properties of the metal. In fact, many properties critical to laser sheet metal forming—such as yield strength and coefficient of thermal expansion—are dependent on temperature and crystallographic orientation, and thus vary considerably during the forming process, complicating bend angle prediction. The effects of temperature and orientation dependence of these properties—and especially the profile of the temperature-property curve—are investigated using a thermomechanical model in the Abaqus finite element modeling software. The models indicate that, while bending is possible even when properties are assumed to be constant with temperature, sharp transitions in temperature-dependent properties can greatly enhance bending, providing a screening metric for the selection of materials for laser sheet metal forming.