【正文】 s. 84 (2020), p. 557. [5] . Hamilton et al., C225。n de metales, 2020 (.). [7] A. Watson, Nickel Sulphamate Solutions, Nickel Development Institute (1989). [8] A. Watson, Additions to Sulphamate Nickel Solutions, Nickel Development Institute (1989). 天津科技大學(xué)外文資料翻譯 12 [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). 外 文 出 處 : 附 件 : 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 mold is an important process on the basis of the manufacturing sector, belong to the special equipment manufacturing industry in the mold and die industry. Although China has already started making the molds and the use of molds, but longterm without the formation of industry. Until the late 1980s, China39。 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。 and with a temperature of 45 176。 this is the reason why it is necessary for the shell to have a thickness as homogeneous as possible (above a minimum value) and with absence of important failures such as pitting. Fig. 2. Hardness variation with current density. pH 4 177。 55 2 177。 etch it begins to appear the rounded grain structure although it is very difficult to check the roads at this time. Besides, the most darkened areas indicate the presence of pitting by inadequate conditions of process and bath position. Fig. 3. Series 1 (150), etch 1. 天津科技大學(xué)外文資料翻譯 21 Fig. 4. Series 2 (300), etch 2. Fig. 5. Series 3 (300), etch 2. This behavior indicates that, working at a low current density and a high temperature, shells with a good reproducibility of the model and with a small grain size are obtained, that is, adequate for the required application. If the analysis is carried out in a plane transversal to the deposition, it can be tested in all the samples and for all the conditions that the growth structure of the deposit is laminar (Fig. 6), what is very satisfactory to obtain a high mechanical resistance although at the expense of a low ductibility. This quality is due, above all, to the presence of the additives used because a nickel sulfamate bath without additives normally creates a fibrous and nonlaminar structure [9]. The modification until a nearly null value of the wetting agent gave as a result that the laminar structure was maintained in any case, that matter demonstrated that the determinant for such structure was the stress reducer (Allbrite SLA). On the other hand, it was also tested that the laminar structure varies according to the thickness of the layer in terms of the current density. 天津科技大學(xué)外文資料翻譯 22 Fig. 6. Plane transversal of series 2 (600), etch 2. 6. Internal stresses One of the main characteristic that a shell should have for its application like an insert is to have a low level of internal stresses. Different tests at different bath temperatures and current densities were done and a measure system rested on cathode flexural tensiometer method was used. A steel testing control was used with a side fixed and the other free (160 mm length, mm width and thickness mm). Because the metallic deposition is only in one side the testing control has a mechanical strain (tensile or pressive stress) that allows to calculate the internal stresses. Stoney model [10] was applied and was supposed that nickel substratum thickness is enough small (3 μm) to influence, in an elastic point of view, to the strained steel part. In all the tested cases the most value of internal stress was under 50 MPa for extreme conditions and 2 MPa for optimal conditions, an acceptable value for the required application. The conclusion is that the electrolitic bath allows to work at different conditions and parameters without a significant variation of internal stresses. 7. Test of the injection mold Tests have been carried out with various representative thermoplastic materials such as PP, PA, HDPE and PC, and it has been analysed the properties of the injected parts such as dimensions, weight, resistance, rigidity and ductility. Mechanical properties were tested by tensile destructive tests and analysis by photoelasticity. About 500 injections were carried out on this core, remaining under conditions of withstanding many more. In general terms, important differences were not noticed between the behavior of the specimens obtained in the core and the ones from the machined cavity, for the set of 天津科技大學(xué)外文資料翻譯 23 the analysed materials. However in the analysis by photoelasticiy (Fig. 7) it was noticed a different tensional state between both types of specimens, basically due to differences in the heat transference and rigidity of the respective mold cavities. This difference explains the ductility variations more outstanding in the partially crystalline materials such as HDPE and PA 6. Fig. 7. Analysis by photoelasticity of injected specimens. For the case of HDPE in all the analysed tested tubes it was noticed a lower ductility in the specimens obtained in the nickel core, quantified about 30%. In the case of PA