## 3 Results and Discussion
### XRD and EDS Analysis
When it comes to the effect of thickness, by comparing the samples supported by AT80G80 and AT33G80, higher thickness value resulted in higher lattice parameter size and in turn higher level of dissolution but less amount of precipitation of secondary phases. The same trend can be seen for the samples fabricated by AT60G100 and AT33G100 supports. This observation can be attributed to the heat transfer and cooling rate conditions vary among different types of support structures. It has been revealed that a higher cooling rate reduces the precipitate formation which leads to reduced precipitation hardening [70]. Since the area of contact between the support and the main part is directly proportional to the amount of heat conducted during the fabrication process, cooling rate and heat dissipation were affected by the type and shape of the support structure. To compare the level of energy dissipation via different support structure, the bottom and top area of the different supports which were in contact with the building plate and main part respectively are presented in Table 3. As the area of contact between the support structure and main part (top area) increased in order (PT53G80 \(<\) CT53G80 \(<\) AT53G80), the cooling rate of the supports would be increased according to the Fourier law of heat conduction [71]. The highest and lowest cooling rate can be estimated for the angled-type and pin-type supports owing to lesser and more precipitation on the samples fabricated with the respective supports. This can also be corroborated by the increasing volume of the supports with PT53G80 having the lowest volume and AT53G80 having the highest. As the volume of the support structure increases, more material will be present underneath to absorb the heat from a sintered layer of the part. Furthermore, AT80G80 with a higher thickness value and then higher contact area compared to AT33G80 resulted in the fabrication of samples with lower and higher amounts of precipitates, respectively. The same conclusion is true when AT33G100 and AT60G100 are compared. In terms of the effect of gap value, a higher level of precipitation can be expected for the AT33G100 with less contact area compared to AT33G80. It should be noted that this variation in the proportion of phases and precipitation levels can bring about different mechanical properties such as strength and ductility and then should be adjusted based on the desired application. Using the proper type of support structure, as observed here, can play a more important role to control the properties of the as-fabricated part. Table 4 lists the EDS measured chemical compositions at the core of columnar dendrites that were obtained from identical samples with different support structures. As revealed from Table 4, the Ni element content has the highest value of 57.3 wt.% in the pin-type supported sample (PT53G80). This rate was dropped considerably for the angled-type support (AT53G80) with existing of the other elements being observed. [PERSON] and [PERSON] [19] found out that the Ni content increased by the increase in the energy input during the LPBF process of IN718 samples. A similar trend was observed in this study, as the highest Ni percentage can be seen for the sample fabricated on support with less contact area, which results in lower heat dissipation rate and thus longer heat accumulation (PT53G80). This condition resembled the fabrication of samples with a higher level of energy density. In terms of the effect of thickness, the same trend was observed by comparing the samples fabricated with AT33G80 and AT80G80 supports. A 5.5 percentage drop in Ni content was found for the sample fabricated on thicker support, which can be attributed to the larger contact area and higher cooling rate. However, the Ni content didn't change when the thickness increased from 0.33 mm in AT33G100 to 0.60 mm in AT60G100. Increasing the gap, however, increased the Ni content by more than 4 percent, which can be explained using the same logic discussed.