*This study investigated the powder thermal conductivity of 17-4PH stainless steel that was encapsulated into hollow specimens with different internal geometries in laser powder bed fusion (L-PBF) additive manufacturing. The objective of this study is to evaluate the effect of the internal geometry of the hollow specimens on the measurement of the powder thermal conductivity; meanwhile, to compare the thermal properties amongst three different powder materials commonly used in L-PBF. Continued with the previous study* *\[1\], three new cone configurations in the hollow specimens were designed and fabricated in an L-PBF system. Then, the thermal conductivity of the internal powder was examined using an experimental-numerical approach, combined with a laser-flash test, FE heat transfer modeling and multivariate inverse method. The results reveal that the powder conductivity of 17-4PH ranges from 0.67 to 1.34 W/(m∙K) at 100 °C to 500 °C, varied upon different internal geometries of the specimens. In addition, the measurement in the hollow specimen with a spherical cap-shaped cone (Convex) reveals a more reliable evaluation. Similar to nickel-based super alloy 625 (IN625) and Ti-6Al-4V (Ti64) powders, the thermal conductivity ratio to the solid counterpart of 17-4PH is approximately ranging from 3.9 % to 5.5 % at tested temperatures.*


Powder Thermal Conductivity Measurements in L-Pbf Using Powder-Included Build Specimens: Internal Geometry Effect

Division / Sponsor: 
Manufacturing Engineering Division (MED)

International Manufacturing Science and Engineering Conference - Paper Proceedings: https://asmedigitalcollection.asme.org/MSEC/MSEC2020/volume/84256

JSME 2020 Conference on Leading Edge Manufacturing/Materials and Processing - Paper Proceedings: https://asmedigitalcollection.asme.org/lemp/LEMP2020/volume/83624

MSEC2020 - Virtual Conference, LEMP2020 - Virtual Conference

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