Process repeatability and sources of error in indirect SLS of aluminium

Abstract

Purpose

The purpose of this paper is to investigate the accuracy and repeatability of the indirect selective laser sintering of aluminium process.

Design/methodology/approach

This work characterised the shrinkage of indirect SLS aluminium parts during the various stages of production. Standard scale parts were measured using a Giddings and Lewis co‐ordinate measuring machine in both the green and infiltrated condition.

Findings

The experiments conducted show that most accuracy is lost during the furnace cycle and that the greatest loss of accuracy occurred in the Z dimension. Additionally the position of parts within the part bed in both X, Y and Z is shown to influence accuracy, with smaller parts being built closer to the edge of the bed later in the build. These results have been interpreted as being a result of the phenomenon of “Z‐growth”. Finally, the research shows that the overall accuracy of the indirect selective laser sintering of aluminium process is comparable with many existing processes such as investment casting.

Originality/value

Before any new material can be accepted, there is a need to not only fully characterise the dimensional accuracy attainable, but also to gain a thorough understanding of the processes that contribute to the inaccuracies. This paper addresses this need.

Citation

Hopkinson, N. and Sercombe, T.B. (2008), "Process repeatability and sources of error in indirect SLS of aluminium", Rapid Prototyping Journal, Vol. 14 No. 2, pp. 108-113. https://doi.org/10.1108/13552540810862073