Additive manufacturing has recently become the state-of-the-art in processing technologies due to the large freedom in design flexibility it offers, and its enablement of manufacturing metal parts cost-effectively. Powder bed fusion, selectively fusing composite powders using a heat source such as a laser or an electron beam is a well-known technology. It has been employed in many industrial sectors including automotive, biomedical, and aerospace [1,2]. 

Optimization of powder bed fusion requires detailed knowledge of the thermal conductivity of powders to control the thermal behavior in manufacturing procedures. So far, there have been only a few studies regarding thermal conductivity measurements of metal powder beds. Several factors influence the effective thermal conductivity values. For example, L. C. Wei et al. unveiled the temperature and type of infiltrating gas dependency on effective thermal conductivities of metal powder beds, especially focusing on the effect of infiltrating gas pressure [3]. In addition, M. Liu et al. investigated temperature and particle size distribution dependency of the effective thermal conductivities of metal powder beds [4]. However, there has not been a study of particle morphology and powder composition dependence on the effective thermal conductivity of metal powder beds. 

In this work, we present the dependence of effective thermal conductivity on the particle morphology of metal powder beds. For systematic analysis, we consider three different types of powder beds with different morphology including Cu, AlSi₁₀Mg, and SS316L. Furthermore, we include differential scanning calorimetry (DSC) and transient plane source (TPS) to measure the effective conductivity. Several factors affecting the measurements of the effective thermal conductivity of powder beds are discussed. 

References

[1] C. Tan et al., International Journal of Machine Tools and Manufacture, 2023, 189, 104032.

[2] M. A. Obeidi, Results in Engineering, 2022, 15, 100473. 

[3] L. C. Wei et al., Additive manufacturing, 2018, 21, 201-208.

[4] M. Liu et al., Powder Technology, 2022, 401, 117323.