Patent ID: 8776372
Filing Date: 2014-07-15
Classification: B21K,B60B,Y10T

Abstract:
1. A method for fabricating a cast magnesium alloy wheel having thickness and enhanced fatigue resistance and intended for use on an automotive vehicle, the wheel having a designed structure comprising a hub connected to a rim by a plurality of spaced radial spokes, where magnesium alloy castings of the designed wheel structure comprise inherently fatigue-prone regions, the fatigue-prone regions having a thickness, the method consisting essentially of: casting a wheel of a selected magnesium alloy using a selected casting process; thermoplastically working the inherently fatigue-prone regions of the as cast wheel by friction stir processing in the solid state to refine the grain size and enhance the fatigue performance of the wheel, the thermoplastic working extending substantially through the thickness of the wheel at the fatigue-prone regions; and then machining the wheel to remove any surface roughening due to friction stir processing and to render a desired surface finish and topography.