Recovery processing method for waste Ti or Ti alloy powder in additive manufacturing

Abstract

The invention relates to a recovery processing method for waste Ti or Ti alloy powder in additive manufacturing. Under inert gas shielding and an indoor temperature condition of 10-20 DEG C, the wasteTi or Ti alloy powder is processed by the steps that (1) sodium amalgam is added into the waste Ti or Ti alloy powder in additive manufacturing, so a mixed sizing agent is obtained; (2) the mixed sizing agent obtained at the step (1) is mixed, so the mixed sizing agent can reach a fluidized state; (3) an inert gas is fed into the mixed sizing agent in the fluidized state, shear friction is motivated to generate the Ti or Ti alloy powder and evaporation of sodium amalgam in the sizing agent is accelerated through convection effects between bubbles generated in the mixed sizing agent and the sizing agent, so solid Ti or Ti alloy powder is obtained through separation; and (4) the Ti or Ti alloy powder obtained at the step (3) is cleaned and dried, so the Ti or Ti alloy powder which can be reused in additive manufacturing is obtained.

Description

technical field [0001] The invention belongs to the technical field of metal powder waste treatment, and in particular relates to a method for recycling and treating waste titanium or titanium alloy powder in additive manufacturing. Background technique [0002] Metal additive manufacturing is a manufacturing technology that uses laser or electron beam as a heat source, and uses preset or synchronously supplied metal powder as a material to accumulate layer by layer on a substrate to form metal parts. Titanium and titanium alloys are the most widely used powders in the field of additive manufacturing. During the additive manufacturing process, titanium or titanium alloy powder that is not directly heated by the heat source will remain in the powder bed and continue to be used as a raw material. However, after repeated use of titanium or titanium alloy powder in the powder bed, the sphericity will decrease, sintering and bonding, the surface will become rough, and the conten...

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Problems solved by technology

[0005] However, although these powder processing methods, such as ball milling or gas agitation, can improve the hollow defects of the powder, they will inevitably lead to changes in the macroscopic shape of the powder such as collapse and cracking, so that the powder no longer has a spherical shape, which is not conducive to the reuse of the powder ; The gas stirring treatment reduces the fine satellite powder attached to the surface of the powder material without changing the macroscopic shape of the powder, but it cannot achieve the reduction of the powder impurity content, especially the oxygen content; the ultrasonic pickling method treats the titanium powder, although The surface morphology and composition of the powder can be improved at the same time, but due to the huge specific surface area of ​​the powder, it will make the reaction process difficult to control, and the treated titanium or titanium alloy powder will cause serious mass loss, and will also cause the powder Hydrogen absorption causes embrittlement in the pickling environment, and the original physical and chemical properties are lost; the active metal vapor reduction method reduces the oxygen content of the powder, and generally requires maintaining a high-temperature reaction environment, which will lead to sintering between powders and changes in powder morphology. At the same time, the high-temperature reaction environment will also cause the diffusion of active metal elements to the inside of the powder. Finally, the remaining active metals on the surface of the powder still need to be removed by pickling, which will inevitably cause the powder to absorb hydrogen and cause embrittlement.

[0006] From the above analysis, it can be seen that there is no mature recycling treatment method for the waste powder of additive manufacturing in China.

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