1：Experimental Design and Method Selection:

Butt welding experiments were conducted on 3 mm thick Ti–6Al–4V specimens with different preset ratios of Al and Si powders using a 4 kW fiber laser. The distribution of Al solute element and its influence on the microstructure and mechanical properties were investigated.

2：Sample Selection and Data Sources:

Ti–6Al–4V alloy plates with specific dimensions were used as base metal. Different ratios of Al and Si powders were preset on the plates before welding.

3：List of Experimental Equipment and Materials:

A 4 kW IPG YLR-4000 fiber laser, ABB IRB4400 industrial robot, GSE-0410S*F75 spray gun, 3D super-depth digital microscope VHX-1000C, energy dispersive spectrometry (EDS), microhardness Vickers machine, and AG-IC100KN electronic universal tester were used.

4：Experimental Procedures and Operational Workflow:

The alloy powders were added to a PVA solution, sprayed on the Ti–6Al–4V plates, and then welded with butt joint along the longitudinal direction. The microstructure and mechanical properties of joints were investigated post-welding.

5：Data Analysis Methods:

The microstructures and distribution of the Al element were observed using a 3D super-depth digital microscope and EDS. Microhardness and tensile strength tests were conducted, and fracture morphology was observed under SEM.