SOLID-STATE METHODS OF JOINING DISSIMILAR MATERIALS AND PARTS AND SOLID-STATE ADDITIVE MANUFACTURING OF COATINGS AND PARTS WITH IN SITU GENERATED TAGGANT FEATURES

摘要

Solid-state additive manufacturing processes for joining dissimilar materials and parts are described. Processes include feeding a first material through a hollow tool of a solid-state additive manufacturing machine to contact a second material, generating deformation of the materials by applying normal, shear and/or frictional forces using a rotating shoulder of the tool such that the materials are in a malleable and/or visco-elastic state in an interface region, and mixing and joining the materials in that region. The joining can include interlocks of various shapes in the interface region. One or multiple taggants can be included in deposited material and/or layers, which taggants respond when triggered by specific external stimulus, such as becoming visible upon subjecting to light of a particular wavelength, heating, electric field, and so on. Some taggants are capable of multiple levels of security effects which can be seen by the naked eye or by using special detectors/readers.