【正文】 , pp. 186– 196. [2] . Yarlagadda, . Ilyas and P. Chrstodoulou, Development of rapid tooling for sheet metal drawing using nickel electroforming and stereo lithography processes, J. Mater. Process. Technol. 111 (2021), pp. 286– 294. [3] J. Hart, A. Watson, Electroforming: A largely unrecognised but expanding vital industry, Interfinish 96, 14 World Congress, Birmingham, UK, 1996. [4] M. Monz243。n et al., Aplicaci243。n del electroconformado en la fabricaci243。n r225。pida de moldes de inyecci243。n, Revista de Pl225。sticos Modernos. 84 (2021), p. 557. [5] . Hamilton et al., C225。lculos de Qu237。mica Anal237。tica, McGraw Hill (1989). [6] E. Julve, Electrodeposici243。n de metales, 2021 (.). [7] A. Watson, Nickel Sulphamate Solutions, Nickel Development Institute (1989). [8] A. Watson, Additions to Sulphamate Nickel Solutions, Nickel Development Institute (1989). [9] J. Dini, Electrodeposition Materials Science of Coating and Substrates, Noyes Publications (1993). [10] . Judy, Magic microactuators with polysilicon flexures, Masters Report, Department of EECS, University of California, Berkeley, 1994. (cap′. 3). A technical note on the characterization of electroformed nickel shells for their application to injection molds —— aUniversidad de Las Palmas de Gran Canaria, Departamento de Ingenieria Mecanica, Spain Abstract The techniques of rapid prototyping and rapid tooling have been widely developed during the last years. In this article, electroforming as a procedure to make cores for plastics injection molds is analysed. Shells are obtained from models manufactured through rapid prototyping using the FDM system. The main objective is to analyze the mechanical features of electroformed nickel shells, studying different aspects related to their metallographic structure, hardness, internal stresses and possible failures, by relating these features to the parameters of production of the shells with an electroforming equipment. Finally a core was tested in an injection mold. Keywords: Electroplating。 Electroforming。 Microstructure。 Nickel 1. Introduction One of the most important challenges with which modern industry es across is to offer the consumer better products with outstanding variety and time variability (new designs). For this reason, modern industry must be more and more petitive and it has to produce with acceptable costs. There is no doubt that bining the time variable and the quality variable is not easy because they frequently condition one another。 the technological advances in the productive systems are going to permit that bination to be more efficient and feasible in a way that, for example, if it is observed the evolution of the systems and techniques of plastics injection, we arrive at the conclusion that, in fact, it takes less and less time to put a new product on the market and with higher levels of quality. The manufacturing technology of rapid tooling is, in this field, one of those technological advances that makes possible the improvements in the processes of designing and manufacturing injected parts. Rapid tooling techniques are basically posed of a collection of procedures that are going to allow us to obtain a mold of plastic parts, in small or medium series, in a short period of time and with acceptable accuracy levels. Their application is not only included in the field of making plastic injected pieces [1], [2] and [3], however, it is true that it is where they have developed more and where they find the highest output. This paper is included within a wider research line where it attempts to study, define, analyze, test and propose, at an industrial level, the possibility of creating cores for injection molds starting from obtaining electroformed nickel shells, taking as an initial model a prototype made in a FDM rapid prototyping equipment. It also would have to say beforehand that the electroforming technique is not something new because its applications in the industry are countless [3], but this research work has tried to investigate to what extent and under which parameters the use of this technique in the production of rapid molds is technically feasible. All made in an accurate and systematized way of use and proposing a working method. 2. Manufacturing process of an injection mold The core is formed by a thin nickel shell that is obtained through the electroforming process, and that is filled with an epoxic resin with metallic charge during the integration in the core plate [4] This mold (Fig. 1) permits the direct manufacturing by injection of a type a multiple us