Defects produced during selective laser sintering\n(SLS) are difficult to non-destructively detect after\nbuild completion without the use of X-ray-based\nmethods. Overcoming this issue by assessing integrity\non a layer-by-layer basis has become an area of\nsignificant interest for users of SLS apparatus.\nOptical coherence tomography (OCT) is used in\nthis study to detect surface texture and sub-surface\npowder, which is un-melted/insufficiently sintered,\nis known to be a common cause of poor part\nintegrity and would prevent the use of SLS where\napplications dictate assurance of defect-free parts.\nTo demonstrate the capability of the instrument and\nassociated data-processing algorithms, samples were\nbuilt with graduated porosities which were embedded\nin fully dense regions in order to simulate defective\nregions. Simulated in situ measurements were then\ncorrelated with the process parameters used to\ngenerate variable density regions. Using this method,\nit is possible to detect loose powder and differentiate\nbetween densities of �±5% at a sub-surface depth\nof approximately 300 �¼m. In order to demonstrate\nthe value of OCT as a surface-profiling technique,\nsurface texture datasets are compared with focus
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