Phononic crystals belong to metamaterial. Arrayed structures can be formed by the artificially designed unit cell in phononic crystals

which are used to tuning and control the waves from Hz to THz frequency domains. Phononic crystals have good application prospects in the industrial field. The quantitative controlling of the negative refraction

negative reflection and self-collimation of wave needs the design of phononic crystals with complex structures. Additive manufacturing is the most appropriate method to fabricate it. In this paper

the development and industrial application

the additive manufacturing and the manufacturing problems of phononic crystals were reviewed. The relationship between the additive manufacturing and the structural performance of phononic crystals was discussed. The effect of process parameters on melt pool solidification in additive manufacturing was simulated. The unit cell of phononic crystals was fabricated by friction stir additive manufacturing to show the effect of the distortions in manufacturing on band gap characteristics of phononic crystals. The comparison shows that the additive manufacturing can affect the microstructures

mechanical properties

densities and distortions in the fabrication of phononic crystals

which leads to the deviations of structural performance from the theoretical design. The controlling of the mechanical properties and geometrical precisions can help the quantitative controlling of the structural performance and band gap characteristics of the additive manufactured phononic crystals.