## 2 Experimental
### Characterization Method  
The annealing treatment of samples L1-L8 is as follows (the sample L7 and the sample L8 are processed according to Figure 4):  
* Samples L1-L6 are heated to 950 \({}^{\circ}\)C and kept for 15 h;
* Sample L7 part A is heated to 850 \({}^{\circ}\)C and kept for 3 h;
* Sample L7 part B is heated to 850 \({}^{\circ}\)C and kept for 3 h;
* Sample L7 part C is not annealed;
* Sample L8 part B is heated to 850 \({}^{\circ}\)C and kept for 3 h;
* Sample L8 part C is not annealed.  
First, the heat-treated samples L1-L6 are processed parallel to the building direction (z-direction) to obtain 2 mm thick specimens for XRD, SEM, and 3 mm \(\times\) 3 mm \(\times\) 3 mm test blocks for DSC tests. The process of sample 7 and sample 8 is cumbersome, so we use Figure 4 to show it. Sample L7 and sample L8 are processed as follows according to Figure 4:  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**SampleParameter** & \(P\) **(W)** & \(v\) **(mm/min)** & **(mm)** & **(mm)** & **(J/mm\({}^{3}\))** & **Specimen Size** \\ \hline L1 & 1500 & 900 & 5 & 0.3 & 66.67 & \\ L2 & 2000 & 900 & 5 & 0.6 & 44.44 & \\ L3 & 2500 & 900 & 5 & 0.9 & 37 & \\ L4 & 1500 & 1000 & 5 & 0.3 & 60 & \\ L5 & 2000 & 1000 & 5 & 0.6 & 40 & \\ L6 & 2500 & 1000 & 5 & 0.9 & 33.33 & \\ \hline L7 & 2000 & 900 & 5 & 0.4 & 66.67 & \(70\times 15\times 12\) \\ L8 & 1500 & 900 & 5 & 0.3 & 66.67 & \\ \hline \hline \end{tabular}
\end{table}
Table 1: LSF parameter combination for preparing NiTiNb.  
Figure 3: NiTiNb prepared by LSF under different parameters. (The specimen size: L1–L6 20 mm \(\times\) 10 mm \(\times\) 10 mm; L7–L8: 70 mm \(\times\) 15 mm \(\times\) 12 mm).  
Figure 2: Scanning strategy.  
we separate sample L7 and sample L8 from the substrate. For sample L7, we cut the tensile samples in part A and the CMT5205 electronic universal testing machine is used to test the L7 sample tensile property at 0 \({}^{\circ}\)C, all specimens are mechanically polished before testing. In part B, we take test block 1 which is parallel to the building direction (z-direction), take test block 2 (from z = 1 mm to z = 3 mm), block 3 (from z = 3 mm to z = 5 mm) and block 4 (from z = 9 mm to z = 11 mm), separately; In part C, we take test block 5 (from z = 1 mm to z = 3 mm) and block 6 (from z = 9 mm to z = 11 mm), separately. For sample L8, we take test block 7 (from y = 0 to y = 20 mm), block 8 (from y = 20 mm to y = 50 mm), and block 9 (from y = 50 mm to y = 70 mm) which are perpendicular to the building direction (z-direction) in part B, and take test block 10 (from y = 0 to y = 20 mm) and block 11 (from y = 50 mm to y = 70 mm) which are perpendicular to the building direction in part C. Secondly, after L1-L8 samples are processed, grinded on sandpaper, polished to obtain a mirror surface, and corroded (the corrosion solution is composed of hydrodynamic acid, nitric acid, and water at a ratio of 1:2:10), then are used for SEM observation, XRD observation, and DSC test (3 mm \(\times\) 3 mm \(\times\) 3 mm test blocks). The ZEISS Sigma 300 scanning electron microscope microscopy and LEICA vertical optical microscope are used to reveal the microstructure of LSF-NiTiNb. Phase structure is examined by SHIMADZU polycrystalline X-ray diffraction with Cu K\(\alpha\) radiation, the 2-theta is scanned in the range of 5-130 \({}^{\circ}\)C with a scan rate of 10 \({}^{\circ}\)/min. Phase transformation temperature is investigated by Netzsch DSC214 differential scanning calorimetry at a heating or cooling rate of 10 \({}^{\circ}\)C/min from \(-\)150 \({}^{\circ}\)C to 150 \({}^{\circ}\)C.