PSI - Issue 14

Anigani Sudarshan Reddy et al. / Procedia Structural Integrity 14 (2019) 449–466 Author name / Structural Integrity Procedia 00 (2018) 000–000

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Fig. 3. Representative SEM micrographs of DMLS powders along with their corresponding particle size distribution, (a-b) IN718, (c-d) CoCrMo, (e-f) Maraging steel, (g-h) SS316L, (i-j) Ti6Al4V respectively . Figure 5 (a-e) represents optical micrographs of polished and etched surfaces for all alloys in the as printed condition. The microstructures reveal the weld pool with different dimensions (height and width) for all alloys. The height of the weld pool is a manifestation the layer thickness and energy input given to the powder bed. The as printed weld pool width is representative of the laser spot diameter. The height of the weld pools is 2 or 3 times the layer thickness to accommodate proper fusion of present layer with the previous layer. The width and depth of the weld pools for all the 5 monolithic alloys are represented in Figure 5(a-e). Ti6Al4V shows a typical martensitic structure