Process for producing a preform using cold spray

A process for producing a preform by cold spray deposition, the process comprising: providing a starter substrate about a preform axis of rotation, the starter substrate having at least one axial end having a substantially flat deposition surface; rotating the starter substrate about the preform axis of rotation; depositing material onto the deposition surface of the starter substrate using cold spray deposition to form a product deposition surface, the cold spray deposition process including a cold spray applicator through which the material is sprayed onto the deposition surface; successively depositing material onto a respective top product deposition surface using cold spray deposition to form successive deposition layers of the material; and moving at least one of: the cold spray applicator; or the starter substrate and preform product, relative to the other in an axial direction along the preform axis of rotation to maintain a constant distance between the cold spray applicator and the top product deposition surface, thereby forming a preform product of a selected length, wherein the cold spray applicator is moved in a plane perpendicular to the preform axis of rotation so as to deposit material as a substantially flat surface on each respective deposition surface of the starter substrate or product deposition surface of the preform product.