Method for manufacturing non-support laser additive material applied to overhanging structure in metal material

A method for manufacturing a non-support laser additive material applied to an overhanging structure in a metal material, comprising:

• forming a metal non-supported overhanging structure by adopting a laser powder bed melting technology, wherein in a process of laser-melting metal powder layer by layer to form forming layers of the metal non-supported overhanging structure, a high and low power alternating forming strategy is adopted, when a current forming layer is equipped with an overhanging area relative to a previous forming layer, the overhanging area of the current forming layer is formed by a S1 forming strategy;
• when the previous forming layer is equipped with an overhanging area, an area where the overhanging area of the current forming layer overlaps with that of the previous forming layer is formed by a S2 forming strategy;
• and remaining areas are all formed by a S0 forming strategy;
• the S0 forming strategy is a fixed power forming strategy, and an adopted laser power is a densification laser power P0, and the densification laser power P0 is capable of ensuring that metal powder of the current forming layer is fully melted and densified;
• the S1 forming strategy is a low-power forming strategy, and an adopted laser power is a low laser power PL, the low laser power PL is capable of ensuring that the metal powder of the current forming layer is partially melted to form pre-bonded powder, thereby increasing a bonding force between the metal powder, forming a loose bonding state of the metal powder, and reducing a melt infiltration;
• the S2 forming strategy is a high-power forming strategy, and an adopted laser power is a high laser power P+, the high laser power P+ is capable of ensuring that the pre-bonded powder formed by sintering the overhanging area of the previous forming layer is re-melted to fully melt the pre-bonded powder, in a case where the metal powder of the current forming area is completely melted;
• the densification laser power P0, the low laser power PL, and the high laser power P+ satisfy that PL<P0<P+;
• and
• a value for the densification laser power P0 ranges from 125 W to 150 W;
• a value for the low laser power PL ranges from 80 W to 100 W;
• a value for the high laser power P+ ranges from 175 W to 200 W.