Techno-Economic Analysis for Comparing Stereolithography and Wax Injection for Pattern Manufacturing in Investment Casting

Abstract

Abstract Investment casting (IC) is a manufacturing process for making components giving an excellent surface finish, dimensional accuracy, and complex shapes. Despite these benefits, IC requires high cost and lead time for realizing the metallic mold for pattern manufacturing. To avoid the shortcoming of casting processes, Additive Manufacturing (AM) is widely used for fabricating patterns, cores, and molds (Rapid Casting - RC). Several applications concerning rapid investment casting (RIC) through Fused Filament Fabrication (FFF) and Stereolithography (SLA) were developed. However, a techno-economic analysis based on SLA application for RIC is missing. This paper presents a techno-economic analysis regarding SLA adoption for RIC. SLA is compared with wax injection, the traditional approach for realizing wax patterns. The article provides a decision-making tool that supports stakeholders in evaluating when AM is convenient (cost and lead time) for creating wax patterns, considering different production scenarios. For the compared technologies, the authors developed analytical cost models capable of assessing the cost of the entire production process and evaluating the postprocessing phases. The following characteristics were considered: (i) different production volume, (ii) machine load factor, and (iii) parts features (i.e., dimensions and shape). The results show that SLA, for small parts, is more convenient than wax injection when the production volume is higher than 1E+03.