## 3 Results  
Figure 2 shows XRD spectra of the CM247 LC powder, directional solidification [28], and SLM samples. Consistent with findings by [PERSON] et al. [29] and [PERSON] et al. [28], a face-centered cubic (FCC) \(\gamma+\gamma^{\prime}\) phase was detected in all samples. The samples all have the same peak corresponding to the crystallographic planes of (111), (200), and (220), but the intensity varies depending on the control parameters. It can be seen that the directional solidification casting shows a high peak in plane (200) due to the grains grown in the casting direction. In the case of SLM manufacturing, it is possible to estimate how much grain growth has occurred depending on the control parameter. The growth parameters, i.e., laser power (W), \(P\), scan speed (mm/s), \(v\), and layer thickness (mm), \(t\), can be combined into the volumetric energy density (J/mm\({}^{3}\)) using the following equation [30]:  
\[Energy\,density=\frac{P}{vHt} \tag{1}\]  
where \(H\) is the hatch spacing (mm). Figure 3 shows the density with respect to the energy density. The dotted box denotes the density at the same energy density. It can be seen that the density varies even at the same energy density. The blue area indicates a density decrease with an increase in layer thickness at 100 W of laser power and a scan speed of 1200 mm/s. The green area indicates a density decrease with an increase in layer thickness at 100 W of laser power and a scan speed of 1800 mm/s. Overall, the density decreases  
Figure 2: CM247 LC XRD data; (**a**) powder, (**b**) directional solidification [28], (**c**) laser power 100 W, scan speed 1800 mm/s, layer thickness 30 \(\upmu\)m, and (**d**) laser power 150 W, scan speed 1200 mm/s, layer thickness 20 \(\upmu\)m.  
as the layer thickness and scan speed increase. At the same energy density, laser power has the greatest effect on density, followed by layer thickness and scan speed. It is known that the porosity of the cross-section decreases as the density increases, regardless of the building direction, as shown in studies regarding the correlation between energy density and porosity [31; 32]. The thermal conductivity of CM247 LC can be decomposed into the effects of electrons and lattice vibrations, based on kinetic theory:  
\[ \begin{array}{c}k_{total}=k_{electron}+k_{lattice}\\ =L\sigma T+\frac{1}{3}C_{v}U\end{array}  \tag{2}\]  
where \(k\) is thermal conductivity (W/m-K), \(L\) is the Lorenz number (W\(\Omega\)/K\({}^{2}\)), \(\sigma\) is the electrical conductivity (S/m), \(T\) is the absolute temperature (K), \(C_{v}\) is the volumetric specific heat (J/m\({}^{3}\)-K), \(\
u\) is the speed of sound (m/s), and \(l\) is the mean free path (m). Figure 4 shows the electrical and lattice thermal conductivities of a sample fabricated using a laser power, scan speed, and layer thickness of 100 W, 1800 mm/s, and 30 \(\upmu\)m, respectively. The electronic thermal conductivity of the nickel-based superalloy CM247 LC dominates the lattice thermal conductivity. The electronic thermal conductivity, derived from the measured electrical conductivity, does not vary with temperature in either the cross-plane or in-plane direction. However, the lattice thermal conductivity is higher in the in-plane direction than it is in the cross-plane direction. Figure 5a shows the cross-plane and in-plane thermal conductivities according to the density at 800 \({}^{\circ}\)C, clearly showing that as the density increases, so does the thermal conductivity. A decrease in thermal conductivity with porosity is typical [33]. However, the thermal conductivities in the cross-plane and in-plane directions differ, especially at low density. At low densities, the in-plane direction shows higher thermal conductivity than that in the cross-plane direction. The thermal conductivity at 800 \({}^{\circ}\)C is shown in Figure 5b. Similarly, the electronic thermal conductivity in the two directions is the same, but the lattice thermal conductivity is approximately 16.5% higher in the in-plane direction.