RPD 2002 – Advanced Solutions and Development Metallic Prototypes for the Pressure Die Casting Industry Lino, J., Neto R., Paiva R., Paiva B. 1/6 METALLIC PROTOTYPES FOR THE PRESSURE DIE CASTING INDUSTRY F. Jorge Lino, FEUP - DEMEGI, Portugal Rui J. Neto, Inegi, Portugal Ricardo Paiva, Inegi, Portugal Bártolo Paiva, Inegi, Portugal Abstract Very useful engineering models for product development can be rapidly available using Rapid Prototyping technologies. A diversity of industrial sectors can benefit from the use of these technologies, through speed improvement in the product development phase and consequently minimising the time to market. Rapid Prototyping technologies also allow the direct or indirect production of metallic prototypes to be used in the development of fully or semi- functional products, like house ware, kitchen and bathroom taps, sand castings, die castings and components to be produced by pressure die casting for the automotive industry. It is the aim of this work to describe a 3 years experience in the development of metallic conversion techniques, to supply functional metallic prototypes for different national companies. The advantages and the disadvantages of some possible complementary technologies to obtain functional prototypes of products that will be produced by pressure die casting are presented. The “lost model” technique using LOM, Thermoject, SLA “Quick Cast”, and the “lost wax” will be compared in terms of accuracy, speed and costs, with techniques that use silicone and the resin filled moulds, considering the production of pre-series of 3 to 50 prototypes. Introduction Over the last decade, a radical change in the project field have been witnessed, with the traditional 2D processes progressively replaced by CAD systems, which are able to generate three- dimensional models. In systems with parametric modelling capacities, it is possible to start by conceptualising the project, and developing different options with simplicity and quickly. Photo-realistic presentations and computer animations help to change the client’s attitude towards prototypes and to avoid costly investments. Therefore, this first step makes it possible to prevent defects, which otherwise, would only be detected at a later stage of the process [1 2]. However, the design process does not end just because a three-dimensional model was created; these programmes can and should interact with other specialised applications to create a global solution to design and manufacture a product. This is the case of the Rapid Prototyping (RP) and Rapid Tooling (RT) technologies, which enable to create prototypes and pre-series with highly reduced response time to market demands [2-6]. In the development phase of new products to be pressure die casted, there is an absolute necessity in producing functional prototypes, which are obtained with a non-final manufacturing process. These prototypes allowing the simulation of the assembling and functionality of the final parts minimize errors that if detected in a later stage, would produce loss of profits and enlarge the time to market. Traditionally, in worldwide, the most defended process for prototypes materialization is the sand casting in green sand and core sand. This methodology implies two simultaneous projects, the project of the die casted part, with the parting lines, sliding cores, and rational thickness distribution, and the project of the foundry tools in sand, with other drafts, parting lines, core prints and core boxes. This fact creates the problem of compromising the parts qualification, the prototypes delivering time, the injection moulds execution and the delivery of die casted parts [2]. With the introduction in the market, in 1987, of the Rapid Prototyping technologies, with the stereolitography being the first system to be commercialised, other systems like selective laser sintering (SLS), fused deposition modelling (FDM), laminated object manufacturing (LOM) and thermoject, were developed and used in many industrial sectors to reduce the time to market [2, 7]. Nowadays, RP is becoming more or less standard in product development, with prototypes being used for demonstration purposes, visual aid, simple tests, etc. However, many times the prototype has to be manufactured in the same material of the final part, in order to perform functional tests. Although direct production of functional metallic prototypes can be performed using the direct metal laser sintering (DMLS) or SLS metals processes [2, 7], the prototypes can only be obtained in the patented alloys developed by these equipment manufacturers, and are very expensive, significantly limiting their use. For this reason, there is a tremendous interest in converting the RP models into metal models, which can be done combining the RP and the investment casting technologies.