Gas turbine blade manufacturing by use of epoxy resin tooling and silicone rubber molding techniques

Abstract

Purpose

Conventional investment casting of turbine blades is a time consuming and expensive process due to the complications in wax injection steps and the complex shape of airfoil surfaces. By using rapid investment casting, a substantial improvement in the gas turbine blade manufacturing process can be expected. However, this process needs to be able to compete with conventional investment casting from a dimensional accuracy view of point. The purpose of this paper is to investigate the manufacture of gas turbine blades via two indirect rapid tooling (RT) technologies, namely epoxy (EP) resin tooling and silicon rubber molding.

Design/methodology/approach

The second stage blade of a Ruston TA 1750 gas turbine (rated at 1.3 MW) was digitized by a coordinate measuring machine. The aluminum‐filled EP resin and silicon rubber molds were fabricated using StereoLithography master models. Several wax patterns were made by injection in the EP resin and silicone rubber molds. These wax patterns were utilized for ceramic shell fabrication and blade casting.

Findings

Dimensional inspection of cast blades showed that silicone rubber molding was not a suitable approach for production of blade wax patterns. The maximum deviation for the final cast blade made using the silicone rubber mold was +0.402 mm. The maximum deviation for the final cast blade made using the EP resin mold was lower at −0.282 mm. This showed that EP resin tooling could enable new cost‐effective solutions for small batch production of gas turbine blades.

Practical implications

The research results presented will give efficient industrial approach and scientific insight of the gas turbine blade manufacturing by use of rapid technologies.

Originality/value

There are some general research works related to utilization of rapid technologies for manufacturing of gas turbine blade. However, this paper presents a unique procedure of integrated reverse engineering and RT technologies for rapid investment casting of gas turbine blade through presenting comprehensive comparison between two techniques from dimensional accuracy view of point.

Citation

Vaezi, M., Safaeian, D. and Chua, C.K. (2011), "Gas turbine blade manufacturing by use of epoxy resin tooling and silicone rubber molding techniques", Rapid Prototyping Journal, Vol. 17 No. 2, pp. 107-115. https://doi.org/10.1108/13552541111113853