Laser solid forming of TB18 titanium alloy was carried out by BLT-C1000 SLM additive manufacturing equipment. The effects of laser power

scanning speed and powder feeding amounts on the microstructure and morphology characteristics of single channel deposition layer and block were investigated by three-factor and three-level orthogonal test method

and the forming parameters were optimized. The results indicate that the single channel deposition layer is characterized by columnar grain

and the width to height ratio is increased with the increase of scanning speed and laser power and the decrease of powder feeding amount

of which the influence degree is in the sequence of scanning speed>laser power>powder feeding amounts. The microstructure of the block is characterized by two-state. With the increase of scanning speed

the microstructure of the alloy is transformed from the two-state microstructure with distinct α+β phase to that with uniform distribution of secondary α phase in the β matrix. In order to obtain desirable microstructure

the optimal parameters of forming process is scanning speed of 800～1 000 mm/min

laser power of 3.0～3.5 kW and powder feeding rate of 25～30 g/min.