The invention relates to hollow balls having shells comprising a sintered inorganic material, such as metals, metal oxides or ceramic, and to methods for producing lightweight structural components using such hollow balls. According to the object of the invention, the application area is to be widened, processing to form structural components is to be made technologically simpler and the properties of the hollow balls and of the structural components produced therewith are to be improved for specific applications. For this purpose, an additional solid functional layer is formed on a shell on the hollow balls. The functional-layer material can then be made able to flow and plastically and/or elastically deformed as a result of a physical and/or chemical treatment.