3D Printing Nozzle System Suitable For Amorphous Alloy Processing In Space Environment

With the continuous advancement of aerospace technology,spacecraft has become an indispensable carrier for various countries' communications,meteorology,space resource exploration,scientific research,military objectives,and manned flight.It is also a manifestation of the comprehensive scientific and technological strength of various countries.However,the severe service environment such as atomic oxygen in space,thermal cycling,space radiation,ultra-high vacuum,micrometeoroids and space debris impacts poses a great risk of serious damage to the spacecraft.In addition,with the development of modern science and technology,people are increasingly calling for the on-orbit manufacturing of metal parts for space equipment.However,the conditions of microgravity cannot satisfy the implementation of laser 3D printing technology using powder as a raw material.Looking for a new space material or new 3D printing technology will help solve the above-mentioned problems faced by space manufacturing.Compared with traditional crystalline metals,the disordered atoms unique to amorphous alloys constitute an internal structure without grain boundaries and dislocations,which can effectively prevent atomic oxygen erosion and spatial radiation aging;the low friction coefficient and low friction of amorphous alloys The surface of the adhesion coefficient can avoid the cold welding phenomenon caused by ultra-high vacuum;the high strength and high wear resistance of the amorphous alloy are suitable for resisting the impact of micro meteors and space debris.Therefore,the amorphous alloy is a new type of alloy that is extremely suitable for space environment applications.In addition,the amorphous alloy exhibits superplasticity in the supercooled liquid region,and previous studies have shown that the supercooled liquid amorphous alloy can achieve metallurgical welding under certain pressure conditions,which brings space 3D printing technology for the development of amorphous alloys.Dawn.This study first designed a supercooled liquid amorphous alloy 3D printing nozzle system based on the superplasticity of the amorphous alloy in the supercooled liquid region.The system first heats the amorphous alloy strip to a supercooled liquid,and then attempts to weld the strip using external force.The results show that because the strip is larger than the surface and dissipates heat quickly,the surface temperature of the two strips in contact is quickly lower than the glass transition temperature,and welding cannot be achieved under high viscosity conditions.In addition,in the air environment,the oxygen enriched in the surface layer of the amorphous alloy hinders the diffusion of atoms,thereby limiting the metallurgical bonding between the amorphous alloy strips.To this end,this study proposes another nozzle design scheme,the principle is mainly to synchronize the laser with the nozzle,and the laser is always focused on the welding point.During the 3D printing process,the material in the area where the laser spot is located melts and welds instantaneously to achieve additive Manufacturing.The spray head is also designed with a special feeding mechanism,which can meet the continuous feeding of strips and bars.The nozzle system can also be used for 3D printing of other metal materials under the conditions of raw material size and melting temperature,which greatly improves the range of alloy selection.