Design, manufacturing and performance OF Fe–Mn–Si–Ni–Cr shape memory seamless couplings

ESQUIVEL, I.; MALARRIA, J.; DRUKER, A.V.

Advances in Industrial and Manufacturing Engineering

Elsevier

Lugar: Amsterdam; Año: 2021 vol. 3 p. 100061 - 100080

2666-9129

The Fe-Mn-Si shape memory (SM) alloyshave attracted a great deal of interest due to their good technologicalcharacteristics and mechanical properties, combined with the SM effect. Theyare especially useful for applications like shaft and pipe couplings. In this work,we present the development and evaluation of a procedure to manufacture SMseamless couplings. After analysing industrial forming methods, we designed andfabricated a prototype of a punch-extrusion (PE) die and obtained seamless tubesof satisfactory quality and length for manufacturing couplings. Finally, wemeasured the performance and SM properties of the PE couplings and compared thesecharacteristics to those of couplings machined from a cast ingot. We concludedthat a multi-step processing is an efficient solution that mitigated problemsresulting from billet cooling during punching because it allows the alloy to bereheated. The PE couplings that were diametrically expanded 4 % and annealed at700 °C exhibited 75 % shape recovery, while the control samples showed 20 %less recovery. The union of 21 mm diameter shafts by means of PE couplingsannealed at 700 °C showed 40 N-m/cm2 normalized torque transmission, which was25 % greater than that found for the cast ingot couplings. We also analyzed theadvantages of the PE couplings compared to a traditional shrink-fit connection.