Based on the wire laser additive manufacturing

this paper innovatively proposes a new process of additive manufacturing of laser wobble fuse combined with laser swing welding technology. Firstly

the laser power P

wire feeding speed V

s

and printing speed V

p

are controlled in the process without laser swing

and the appropriate swing frequency f

swing amplitude A and overlap rate η are adjusted under circular swing. A single-channel experiment was performed on TC4 titanium alloy

and it was found by comparison that the deposition quality was better when P = 2500 W

V

s

= 3 m/min

V

p

= 2.5

m/min

f = 300 Hz

A = 1 mm and η = 50%. Based on the single-pass experiment

multi-pass multilayer printing was carried out

and the microstructure and phase of the as-deposited state and after annealing were analyzed by XRD

TEM

SEM and EBSD. The results show that the microstructures are mainly slender acicular martensite α′ and initial columnar β grains under single-pass printing and multi-layer multi-pass printing. In addition

the β grains are irregular in shape

the growth orientation changes obviously

the α′ size is small

and the structure is closely arranged

which is a typical widmanstetten structure. After recrystallization annealing (800 ℃/2 h

furnace cooling)

the grain boundary of α phase appears

and the α phase tends to grow.