1：Experimental Design and Method Selection:

The study involved fabricating a Ti–26Nb alloy using laser additive manufacturing (LAM) with elemental Ti and Nb powders, followed by annealing at various temperatures (650°C to 925°C) to analyze microstructure evolution and mechanical properties. Theoretical models include rapid solidification and diffusion mechanisms.

2：Sample Selection and Data Sources:

Commercial gas-atomized pure Ti powder (45–105 μm) and pure Nb powder (48–75 μm) were mixed in a weight ratio Ti:Nb =

3：

4：5 (atomic ratio

26) by ball milling for 1 hour. Samples were sectioned from the LAM-fabricated block for heat treatment and testing.

5：List of Experimental Equipment and Materials:

Equipment includes a YLS-4000-CL LAM machine (IPG Photonics), optical microscope (OM; BX51M, Olympus), scanning electron microscope (SEM; MIRA3 LMU, Tescan), X-ray diffractometer (XRD; D/max 2500, Rigaku), electron backscatter diffraction system (EBSD; HKL, Oxford), and Instron 5569 universal testing machine. Materials include Ti and Nb powders from Changsha Tianjiu Metal Materials Co. Ltd.

6：Experimental Procedures and Operational Workflow:

Powders were mixed and used in LAM with parameters: laser power 750 W, beam diameter 2.5 mm, scanning speed 480 mm/min, powder feed rate 2.2 g/min. Annealing was done in vacuum at 650°C, 750°C, 850°C, and 925°C for 0.5 hours followed by water quenching. Microstructure characterization and tensile tests were performed.

7：5 mm, scanning speed 480 mm/min, powder feed rate 2 g/min. Annealing was done in vacuum at 650°C, 750°C, 850°C, and 925°C for 5 hours followed by water quenching. Microstructure characterization and tensile tests were performed. Data Analysis Methods:

5. Data Analysis Methods: Microstructure analyzed using OM, SEM, XRD, and EBSD; mechanical properties evaluated through tensile tests with statistical analysis of three samples per condition.