Quantifying accuracy of a concept laser metal additive machine through the NIST test artifact

Abstract

Purpose

The purpose of this paper is to describe the use of a test artifact proposed by NIST to quantify the dimensional accuracy of a metal additive manufacturing process. Insights from this paper are given concerning both the performance of the machine, a concept laser Mlab cusing machine, and the applicability of the NIST test artifact in characterizing accuracy. Recommendations are given for improving the artifact and standardizing a process for evaluating dimensional accuracy across the additive manufacturing industry.

Design/methodology/approach

Three builds of the NIST additive manufacturing test artifact were fabricated in 316 stainless steel on a concept laser Mlab cusing machine. The paper follows the procedure described by NIST for characterizing dimensional accuracy of the additive process. Features including pins, holes and staircase flats of various sizes were measured using an optical measurement system, a touch probe and a profilometer.

Findings

This paper describes the accuracy of printed features’ size and position on the test artifact, as well as surface finish on flat and inclined surfaces. Trends in variation of these dimensions are identified, along with possible root causes and remedies. This paper also describes several strengths and weaknesses in the design of the test artifact and the proposed measurement strategy, with recommendations on how to improve and standardize the process.

Originality/value

This paper reviews a previously proposed design and process for measuring the capabilities of additive manufacturing processes. It also suggests improvements that can be incorporated into future designs and standardized across the industry.

Citation

Weaver, J.M., Barton, T.J., Linn, J., Jenkins, D., Miles, M.P. and Smith, R. (2019), "Quantifying accuracy of a concept laser metal additive machine through the NIST test artifact", Rapid Prototyping Journal, Vol. 25 No. 2, pp. 221-231. https://doi.org/10.1108/RPJ-01-2018-0029