Fabrication of thin-walled tubes from alloy 602 CA using shear assisted processing and extrusion

Thin-walled tubes are usually produced seamlessly via an expensive multi-step process or via welding of thin sheets but at reduced performance. To overcome the current process and performance inefficiencies, advanced manufacturing methods need to be investigated. In this study, shear assisted processing and extrusion (ShAPE) was used to fabricate thin-walled Alloy 602 CA tubes. Tubes measuring 0.83 m length with a 12 mm outer diameter and 1 mm wall thickness were fabricated with an average surface roughness, Ra of 1.6 μm and Rz of 15 μm. Tensile testing of tubes in the as-fabricated condition demonstrated performance comparable to the solution-annealed bar stock. Electron microscopy analysis revealed the recrystallized microstructure with refined inter- and intra-granular carbides. The preliminary results obtained in this study show the feasibility of producing thin-walled high temperature tubes via ShAPE.