Autor(es): Rosado, Pedro M. S. ; Sampaio, Rui F.V. ; Pragana, João P. M. ; Bragança, Ivo ; Silva, Carlos ; Martins, Paulo
Data: 2024
Identificador Persistente: http://hdl.handle.net/10400.21/22105
Origem: Repositório Científico do Instituto Politécnico de Lisboa
Assunto(s): Coin minting; Additive manufacturing; Joining by forming; Experimentation; Finite element
This paper presents a novel manufacturing process for producing innovative bi-material collector coins with free- rotating inner elements. The inner elements are fabricated using additive manufacturing, enabling the creation of coins with complex and intricate geometric details that would be unattainable using conventional wrought materials. The outer elements (rings) are metallic, and this study addresses the challenge of securely connecting them to the inner elements through force-closed mechanisms formed during the coin minting process. Finite element modeling, combined with experimentation on bi-material (polymer-metal and metal-metal) coins, is employed to analyze material flow, assess minting forces, and evaluate contact pressures at the force-closed joints. The analysis ensures that adequate destructive forces are required to separate the inner elements from the rings and provides insights into selecting the appropriate process parameters for simultaneous coining and joining. The successful production of the first bi-material collector coin prototypes with free-rotational inner elements validates the overall development.
