Abstract
Thermal spraying and thixoforging technologies can be combined in a new manufacturing method for the production of light metal matrix composites. Laminated prepregs are produced by coating unidirectional fiber bundles with light metal matrix material. The prepregs are heated up and densified by thixoforging to near net-shape composites. Compared to conventional technologies for the integration of fibers in light metal matrices, like squeeze casting, hot pressing and diffusion bonding, this method offers the possibility to realize complex component geometries with short cycle times. Due to its high deposition rate and reduced thermal load on the substrate, the arc wire spraying technique is used for the coating of fiber bundles with the matrix material (AlSi6). The final fiber volume content of the MMC can be tailored by the thickness of the coating. Prior to the coating process, a continuous fiber strand is coiled on a cylindrical workpiece with adapted dimensions by using a winding unit provided with fiber guiding system. The speed and horizontal range of the fiber guide unit can be continuously varied in order to control overlapping and ensure homogeneous thickness of the fiber layer. An efficient air cooling system is installed in order to control the thermal load, which affects the formation of microcracks and influence the final residual stress distribution in the coating. An innovative method to wind and coat continuous fibers for manufacturing fiber reinforced light metal matrix composites will be presented.