When the linear energy density is t

When the linear energy density is too high, the laser will strongly irradiate the molten pool, resulting in the instability of the molten pool and sputtering of metal droplets to both sides. After solidification, spheroidized metal particles will appear around the scanning track. When the linear energy density is appropriate, the metal powder can form a good pool, the pool and the substrate form a good wetting Angle, the pool with the laser beam moving forward, can form the width and height of the appropriate channel. When the line energy density is too small, the molten pool is unstable in the process of movement, and the molten pool becomes smaller after cooling, with obvious spherification and uneven melting height, resulting in breakpoint and discontinuity in the molten channel