An impact beam assembly includes a beam of high-strength steel, and a pair of end brackets constructed of a dissimilar material than the high-strength steel. The brackets are locally deformed onto the beam to thereby surround a portion of the beam. Once deformed, the brackets define a flat section suitable for welding to a vehicle door panel, as well as a section for retaining the beam. The beam can include a surface feature suitable for retaining the beam to the end brackets. A method of reinforcing a vehicle door assembly includes positioning the beam with respect to the end brackets such that the brackets surround a portion of the beam, and then activating a magnetic pulse coil (MPC) to deform an overlapping portion of the brackets onto the beam. The brackets are then attached to a surface of the door assembly to reinforce the door assembly.