Rapid investment casting: direct and indirect approaches via model maker II

Abstract

Although investment casting (IC) provides an economical method for the mass production of metal parts with complex and intricate features, the relatively long lead times and high tooling costs involved in the manufacture of metal moulds for the fabrication of sacrificial IC wax patterns lead to cost justification problems for customised single casting, small and medium quantity production. The application of rapid prototyping (RP) technologies to fabricate complex sacrificial IC patterns can result in significant reduction in the costs and lead times associated with single part or small quantity production. Previously, the authors assessed the suitability of the fused deposition modelling process, in particular ABS models, for creating sacrificial IC patterns [1]. The current research looks into the feasibility of employing patterns fabricated by Model Maker II (MMII) as sacrificial IC patterns to produce metal castings rapidly. In addition, an indirect approach involving the utilisation of silicone rubber moulding with an MMII-fabricated master pattern to produce sacrificial IC wax patterns is investigated. The dimensional accuracies and surface qualities of the final metal castings generated from the RP-produced patterns are presented. Cost and lead time comparisons are also carried out and presented.

Influence of building orientation on the flexural strength of laminated object manufacturing specimens

“…Additive manufacturing (AM) can be defined as a group of techniques to obtain final parts, prototypes, cores, injection molds for plastics, electrodes for erosion, etc., in a short period of time from a 3D file elaborated with CAD software [1,2]. As a result of these processes, it is possible to carry out, in a relatively short period of time, different specimens and geometries to validate the definitive design, and to undertake the serial production with reduced development times, and with lower development costs.…”

Digital Manufacturing Process Chain for One-Off Replacement Parts: A Precision Casting Case Study

“…It was found to be very useful in that it enables elimination of feeding system designs that are obviously useless as well as focus on promising values of casting parameters. Among all papers, mainly case studies, that were found in literature dealing with rapid casting of parts based on an original to be replicated [1,2,[5][6][7]11,13,16,17,19,25,26,29], all but three tacitly admit that a right-first-time casting can be achieved, obviously by selecting casting feeding and process parameters according to experience. The three exceptions [16,19,29] used simulation to check that the single envisaged casting system design was suitable, i.e., without trying out alternatives.…”

“…In addition, even if the layer thickness is small enough, the resulting fabrication time may be prohibitively large, especially for large parts [7].…”

Direct Investment Casting For Pattern Developed By Desktop 3D Printer

“…The perception of RP to be implemented as sacrificial master pattern in Investment Casting (IC) was dated back in 1989 [1]. Initially, the block mould was used in IC, and the concept is to build the RP parts that required no additional finishing.…”