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For high-quality additive layer manufacturing (ALM) components to be manufactured, high purity homogenous printing material is required. A number of these methods use metal powders as a printing material. The composition of the powders can be controlled by the raw material, but understanding contamination is not so simple.
Powder bed fusion (commonly referred to as 3D printing) is a method of additive layer manufacturing in which a thin powder is selectively bonded; repetition of this process allows 3D structures to be grown. The successive layers of metal powder are selectively bonded by an energy source such as a laser or electron beam which sinters/melts the material.
The integrity of the printed part is linked to the chemical homogeneity. Chemical inhomogeneities can arise from contamination in the metal powder, as the process does not involve large scale melting the contamination will produce a significant local change in composition, not a slight change in the overall chemistry. The contamination will have different melting/sintering properties thus forms a local defect. If there are excessive defects then a component will fail.
EDS chemical analysis can be used to inspect the printing powders to identify contamination, however, the process is like looking for a needle in a haystack. The contaminants are in trace concentrations or not present, thus thousands of powder particles must be inspected just to confirm prove a powder is pure.
AZtecLive introduces a new method of chemical analysis, where chemical information can be displayed as a real-time image, this means that samples of the printing powder be visually inspected in a fraction of the time.
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