# SHS Produced TiB\({}_{2}\)-Si Powders for Selective Laser Melting of Ceramic-Based Composite
## 2 Materials and Methods
### Characterization of Powders and Printed Parts  
Standard feedstock characterization techniques for industry are defined in ASTM F3049 (Standard Guide for Characterizing Properties of Metal Powders), which is specified for the powder metallurgy. Nevertheless, these techniques may be used to estimate powders flowability for AM processing. In this work, the flowability was evaluated using the Hall Flowmeter test as a time of 50 g of powder flowing through the \(\O\)2.5 mm hole in a funnel according to the EVS-EN ISO 4490:2018 standard. At least five measurements were carried out and values were averaged. The particle size distribution was assessed with the help of laser diffraction using a Malvern Mastersizer 3000.  
The bulk density of the prepared composites was measured by [PERSON] method (Mettler Toledo ME204, Australia) using distilled water as the immersion medium. The theoretical density was estimated assuming a rule of mixture and taking the density of TiB\({}_{2}\) and Si as 4.49 g cm\({}^{-3}\) and 2.33 g cm\({}^{-3}\), respectively. Phases analysis of the samples, which were crashed into powders, was performed by X-ray diffraction (XRD) using a Philips X'Pert PRO diffractometer (40 mA, 40 kV, CuK\(\alpha\) radiation, \(\lambda\) = 0.1542 nm, step size of 0.02\({}^{\circ}\), PANalytical, Netherlands) for both powders and as-printed specimens. The XRD peaks were determined from the HighScore Plus software database (ICSD-cross referenced). The relative contents of the phases presented in the structures were estimated by the Rietveld refinement method, which was performed by quantitative analysis of the crystalline phases detected by corresponding XRD patterns (TiB\({}_{2}\)-ICDD card No. 04-002-0799 and Si-ICDD card No. 04-014-8844).  
For microstructural analysis, a field-emission scanning electron microscope (FE-SEM, Zeiss Evo MA15, Germany) equipped with an EDS (energy dispersive spectroscopy) detector was utilized. Samples were subjected to a hot conductive (resin) mounting, polished with the diamond abrasives down to 0.5 \(\upmu\)m finish and coated with a thin layer of Pt for better conductivity.  
Micro-hardness measurements were conducted using the Vickers microhardness tester (Indentec 5030 SKV) at a load of 1 kg for a dwell time of 10 s. The measured hardness value for each specimen was taken as the average of 10 indents.  
The surface roughness analysis was performed by a Keyence VK-X250 profile-analyzing confocal laser microscope (Keyence Corporation, Osaka, Japan). Maximum height (Sz) and arithmetical mean height (Sa) were averaged for four scanned areas with the dimensions of 500 \(\upmu\)m \(\times\) 700 \(\upmu\)m. Sz is a sum of the maximum peak height and the maximum valley depth in the defined area, and Sa is the average value of the absolute height at each point.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**No.** & **Laser** & **Volumetric Energy Density** \\  & **Current(mA)** & **(\(\mathbf{\text{$\cdot$}\text{mm}^{-3}}\))** \\ \hline Cylinder 1 & 1400 & 280 \\ Cylinder 2 & 1800 & 360 \\ Cylinder 3 & 2200 & 440 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Laser current and volumetric energy density applied to produce TiB\({}_{2}\)-Si solid parts.