A method for manufacturing a metallic component includes the steps of providing a component preform of a metallic material, which constitutes the metallic component and a shaping means which defines the shape of the metallic component. The component preform is subjected to Hot Isostatic Pressing for a predetermined time at a predetermined temperature and a predetermined pressure. The shaping means is removed by contacting the component preform with a pickling agent. The step of providing the component preform includes providing the component preform with an acid resistant metal layer, wherein the acid resistant metal layer is applied with electroplating and wherein the acid resistant metal layer is arranged such that it protects the metallic material from contact with the pickling agent.

A method of forming a retention structure including magnetic regions and non-magnetic regions includes positioning one or more magnetic materials over one or more magnets of a rotor assembly and positioning one or more non-magnetic materials over one or more spacers, the spacers being positioned between the one or more magnets. The method also includes forming a cylindrical retention structure sized to fit around the one or more magnetic materials and the one or more non-magnetic materials. Forming the cylindrical retention structure is implemented via a three-dimensional printing process.