# Additive Manufacturing of PH 13-8 Mo Family: A Review
## 5 DED-LB of PH 13-8 Mo Family  
As a difference with PBF-LB and DED-Arc processes, fewer references are available in the literature about DED-LB of the PH 13-8 Mo family. In terms of process parameters, [PERSON] et al. [76] studied the effects of laser energy density on the shape of the depositions of PH 13-8 Mo powder manufactured using DED \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Material**} & \multirow{2}{*}{**Reference** **(Data from)**} & \multirow{2}{*}{**Process**} & \multirow{2}{*}{**Process**} & \multirow{2}{*}{**Condition**} & \multicolumn{2}{c}{**Ultimate**} & \multirow{2}{*}{**Yield**} & \multirow{2}{*}{**Elongation**} & \multirow{2}{*}{**Hardness**} & \multirow{2}{*}{**Coiling**} \\  & & & **Parameters** & & & **Strength** & & (MPa) & & (**MPa) \\ \hline EOS & & & * LP: 259 W & As-Built & - & - & - & 347.7 HV1 & - \\ Stainless Steel & & PBF- & HS: 100 \(\mu\)m & * 58: & A * 530 \({}^{\circ}\)C & - & - & - & 508.3 HV1 & Water quenching \\  & & M290 & 1067 \(\mu\)m/s & for 3 h & & & & & \\ \hline \multirow{4}{*}{PH 13-8 Mo} & [PERSON] et al. [74] & & * AAC: 135 A & As-Built & - & - & - & 401 HV1 & - \\  & & * A: 28 V & * WFS & A: 530 \({}^{\circ}\)C & - & - & - & 428.3 HV1 & Water quenching \\  & & & & * BC: 4 mm/s & 3 h & & & & \\ \hline \multirow{4}{*}{PH 13-8 Mo} & & & AAC: 135 A & As-Built & 1046 & 860 & 14 & \(\begin{array}{c}33.6\pm 1.2\\ \text{HRC}\end{array}\) & - \\  & & & A: 28 V & * WFS: & A: 495 \({}^{\circ}\)C & 1363 & 911 & 16.3 & \(\begin{array}{c}46.4\pm 0.5\\ \text{HRC}\end{array}\) & - \\  & & & TS: 4 mm/s & & & & & \\ \cline{1-1}  & [PERSON]- & [PERSON] et al. & PBF- & LP: 258.7 W & As-Built & 1032 & 929 & 15.3 & \(\begin{array}{c}34.9\pm 2.9\\ \text{HRC}\end{array}\) & - \\  & & LB/ EOS & HS: 100 \(\mu\)m & * 58: & A: 550 \({}^{\circ}\)C & 1738 & 1659 & 14.7 & \(\begin{array}{c}51.2\pm 0.4\\ \text{HRC}\end{array}\) & - \\  & & & 1067 mm/s & 115 min & 1738 & 1659 & 14.7 & \(\begin{array}{c}51.2\pm 0.4\\ \text{HRC}\end{array}\) & - \\ \hline \hline \end{tabular}  
* A: Aging, AAC: Average Arc Current, AV: Arc Voltage, HS: Hatch Spacing, LP: Laser Power, LT: Layer Thickness, SS: Scanning Speed, TS: Travel Speed, WFS: Wire Feed Speed.  
\end{table} 
Table 6: Comparisons of tensile properties and hardness of PBF-LB and DED-Arc of PH 13-8 Mo family. LB. It was observed that low energy density was not so efficient in depositing a suitable geometry due to the lack of heat input to melt all the powder. High walls were produced with higher energy densities; however, heat accumulation led to improper shapes. [PERSON] et al. [77] reported the influence of the process parameters of DED-LB/p on the geometry of deposited, modified PH 13-8 Mo single tracks. Also, the as-built microstructure was investigated. With the help of the design of experiments (DoE), suitable process parameters in terms of the geometrical features of tracks were established. In addition, it was concluded that the height was significantly affected by the powder feeding rate and not significantly affected by the laser power. On the other hand, the width and depth were affected by the laser power. The speed influenced the depth, height, and width. The as-built microstructure consisted of a martensitic matrix, \(\delta\)-ferrite, retained austenite, and aluminium-enriched inclusions. [PERSON] et al. [78] continued and used those suitable parameters to deposit a multi-track single layer of modified PH 13-8 Mo using DED-LB/p. The microstructure was heterogenous, and martensitic matrix, \(\delta\)-ferrite, austenite, and AlN inclusions were observed in the single layer. [PERSON] et al. [79] investigated the microstructure of DED-LB/p/PH 13-8 Mo. The microstructure consisted of cellular, fine dendritic and columnar regions, and a martensitic matrix with embedded \(\delta\)-ferrite was observed. In terms of mechanical testing, limited information is available. [PERSON] et al.