Friction Freeform Fabrication of Superalloy Inconel 718: Prospects and Problems

Autor: J.J.S. Dilip, G.D. Janaki Ram
Rok vydání: 2013
Předmět:
Zdroj: Metallurgical and Materials Transactions B. 45:182-192
ISSN: 1543-1916
1073-5615
DOI: 10.1007/s11663-013-0003-x
Popis: Friction Freeform Fabrication is a new solid-state additive manufacturing process. The present investigation reports a detailed study on the prospects of this process for additive part fabrication in superalloy Inconel 718. Using a rotary friction welding machine and employing alloy 718 consumable rods in solution treated condition, cylindrical-shaped multi-layer friction deposits (10 mm diameter) were successfully produced. In the as-deposited condition, the deposits showed very fine grain size with no grain boundary δ phase. The deposits responded well to direct aging and showed satisfactory room-temperature tensile properties. However, their stress rupture performance was unsatisfactory because of their layered microstructure with very fine grain size and no grain boundary δ phase. The problem was overcome by heat treating the deposits first at 1353 K (1080 °C) (for increasing the grain size) and then at 1223 K (950 °C) (for precipitating the δ phase). Overall, the current study shows that Friction Freeform Fabrication is a very useful process for additive part fabrication in alloy 718.
Databáze: OpenAIRE