Rapid manufacturing of patterns for investment casting: improvement of quality and success rate

Abstract

Purpose

The main objective of this paper is to analyse all stages of the CastForm™ polystyrene (CF) pattern fabrication process, identify the reasons leading to inferior quality, and outline techniques for its improvement and reduction of failures.

Design/methodology/approach

This paper describes rapid manufacturing of patterns for shell or flask investment casting using the laser sintering (LS) technique with CF material. The process involves data preparation, LS fabrication of a “green” part, cleaning, and wax infiltration. All process stages are equally important for successful project completion in terms of pattern quality and delivery time. A failure at any stage requires a part or pattern to be produced again, which would incur additional time and cost.

Findings

The conducted experiments show how the CF material strength varies at different process stages and temperatures. Cleaning and wax infiltration are considered the main reasons for part distortion and breakage.

Originality/value

The paper proposes a new approach for wax infiltration. Deformation and breaking of unsupported features could be reduced or eliminated by introducing a supporting structure under these features.

Citation

Dotchev, K. and Soe, S. (2006), "Rapid manufacturing of patterns for investment casting: improvement of quality and success rate", Rapid Prototyping Journal, Vol. 12 No. 3, pp. 156-164. https://doi.org/10.1108/13552540610670735