Characterization of Surface Fault Patterns with Application to aLayered Manufacturing Process 1

Detection of faults is a continuing need in all manufacturing processes. This need is more pronounced in new manufacturing processes where continual product improvement is desired. In this paper, a systematic approach is developed for addressing this need. Contemporary experimental and surface analysis techniques provide a basis for incrementally diagnosing the fault mechanisms leading to surface deviations. Based on this general approach, a maturing layered-manufacturing process is investigated, notably, Selective Laser Sintering (SLS). We rst show through experimental analysis that layer-thickness and part orientation aaect surface quality. Using these experimental results, random-process analysis is carried out to determine the spe-ciic fault patterns. The quantiication of these fault patterns leads to the identiication of fault sources, which provide a foundation for monitoring and control. The paper concludes with a summary of fault mechanisms on SLS parts, implementation issues for improving part quality, and insights for applying our approach to other manufacturing processes.