PSI - Issue 7

R.D. Xu et al. / Procedia Structural Integrity 7 (2017) 84–91 R. D. Xu, et al. / Structural Integrity Procedia 00 (2017) 000–000

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Fig. 5. Fracture surface SEM images of fatigue specimen with crack initiation site at sub-surface with crystalline interface cracking (a); with surface crack initiation from a defect (b); with no-defect original surface crack initiation site (c) and abraded one (d) 4. Conclusions The goal of this study was to characterize the fatigue behavior of SLM K536 and its relationship to porosity. The major conclusions are summarized as follows:  The uniaxial tensile properties of SLM K536 are signally influenced by the building direction. The UTS and yield stress of X-orientation specimens are higher than those of Z-orientation specimens. Both of the two orientation specimens show a good tensile strength in contrast with the wrought K536 specimens at most temperature.  The fatigue behavior of SLM K536 X-orientation and Z-orientation specimens are similar at elevated temperatures, meaning that the anisotropy of SLM K536 fatigue strength is not apparent.  The scatter in fatigue lives of SLM K536 Z-orientation specimens suggested that it is susceptible to defects, proved by the analysis of fatigue fracture surface. It means that the location of defects in SLM K536 specimens is effect by the building direction, what needs further research. Acknowledgements The supply of materials and financial support from AVIC Commercial Aircraft Engine Co, LTD is gratefully acknowledged. References [1] Levy G. N., Schindel R., Kruth J. P., 2003. Rapid Manufacturing and Rapid Tooling with Layer Manufacturing (Lm) Technologies State of the Art and Future Perspectives. CIRP Annals -Manufacturing Technology 52(2), 589-609. [2] Huang Weidong, Lin Xin, Chen Jing, et al. 2007.In “ Laser Solid Forming ”. Northwestern Polytechnical University Press, Xi’an ． [3] Kumar S., 2014. Selective Laser Sintering/Melting. Comprehensive Materials Processing 10, 93-134.