# Truncated Newton Kernel Ridge Regression for Prediction of Porosity in Additive Manufactured SS316L
## 2 Materials and Methods
### Experimental Results from the Literature
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Authors**} & \multicolumn{5}{c}{**Experimental Conditions**} \\ \cline{2-6}  & \multicolumn{1}{c}{**Machine**} & \multicolumn{1}{c}{**Powder**} & \multicolumn{1}{c}{**Fabricated Parts**} & \multicolumn{1}{c}{**Density/Porosity Measurement Method**} \\ \hline \multirow{4}{*}{[PERSON] et al. [25]} & - & Concept Laser GmbH M2 & \multirow{4}{*}{-} & Two types of SS316L & \multirow{4}{*}{Pillars of surface area 10 \(\times\) 10 mm\({}^{2}\).} & Archimedes method and scanning electron microscope. \\  & - & Processes performed at room temperature. & & & \\  & - & Machine has a 400-W & & & \\  & - & fiber laser. & & & \\ \hline \multirow{4}{*}{[PERSON] et al. [26]} & - & Concept Laser GmbH M1 & - & Powder M and 16-45: & \multirow{4}{*}{Archimedes method and scanning electron microscope.} \\  & & machine equipped with an & & Gaussian particle size & \\  & & Nd: YAG solid-state laser. & distribution. & & \\  & - & Maximum laser power of & - & Powder 1.4404–CL20: & \multirow{4}{*}{\(5\times 5\times 5\) mm\({}^{2}\).} & \\  & - & 105W. & & Asymmetric & \\  & - & Chessboard-like structure & distribution. & & \\  & - & scan strategy. & & & \\ \hline \multirow{4}{*}{[PERSON] et al. [27]} & - & Concept Laser GmbH & - & SS316L CL20 ES & \multirow{4}{*}{Archimedes method.} \\  & & Mlab-Cusing under Argon & & powder. & \\  & & atmosphere. & - & Spherical & \\  & - & Machine equipped with & & morphology and & \\  & & Yb:YAG fiber laser, effective & & irregularly shaped & \\  & & power of 100 W. & & particles. & \\  & - & Line scanning strategy. & - & Narrow particle size & \\  & - & Processes performed at room temperature. & & distribution. & \\ \hline \multirow{4}{*}{[PERSON] et al. [28]} & - & Concept Laser GmbH & \multirow{4}{*}{-} & \multirow{4}{*}{Maximum grain size of 50 μm.} & Relative density was \\  & & Mlab-Cusing equipped with & & determined from an & \\  & & Nd:YAG fiber laser. & & & \\  & - & Maximum power of 100 W. & & & \\  & - & Building volume is 90 \(\times\) 90 & & & \\  & & \(\times\) 80 mm\({}^{3}\). & & & \\  & - & EOS GmbH M290 machine. & - & Gas-atomized 316L & \multirow{4}{*}{Rectangular prisms} & Light optical \\  & - & Ar environment and oxygen & & powder. & \\  & - & content below 0.1\%. & - & Size distribution of & 72 \(\times\) 12 \(\times\) & microscopy \\  & - & Stripe scanning scan strategy. & & 25-53 μm. & 2.5 mm\({}^{3}\). & micrographs. \\ \hline \multirow{4}{*}{[PERSON] et al. [30]} & - & SLM Solutions GmbH under & \multirow{4}{*}{-} & Gas-atomized 316L & \multirow{4}{*}{-} & Horizontally \\  & & Argon atmosphere. & & powder. & built Blocks. & Scanning electron \\  & - & Equipped with fiber laser & - & Different particle size & \\  & - & Automatic powder layering & distributions. & & \\  & - & mechanism. & & & 10 \(\times\) 6 mm\({}^{3}\). & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Summary of experimental conditions of studies used for data collection. The data extracted from the literature are combined with the experimental data of the current study to create predictive models for the relative density of SS316L parts fabricated by SLM. The extracted and compiled datasets enable the generalization of the similarities among different AM machines and aid in understanding the correlation between the process parameters and the relative density of the parts using ML techniques.