Ultrafast-continuous laser asynchronous polishing powder feeding additive manufacturing metal surface process

Abstract

The invention provides an ultrafast-continuous laser asynchronous polishing powder feeding additive manufacturing metal surface process. The ultrafast-continuous laser asynchronous polishing powder feeding additive manufacturing metal surface process comprises the following steps of performing laser micro-milling on the surface of a powder feeding additive manufacturing metal material by using ultrafast laser, and removing a macroscopic convex deposition layer on the surface of the powder feeding additive manufacturing metal material to obtain a sample piece with a flat processing surface; putting the sample piece into an oxygen isolation container, introducing protective gas, performing laser polishing on the machined surface of the sample piece by utilizing the continuous laser, heatinga machined surface material to a molten state, forming material micro-flow by surface tension of a liquid material, removing micro-morphology left by laser micro-milling, and performing cooling and solidifying to form a smooth surface; and achieving surface polishing of the surface of the powder feeding additive manufacturing metal material from large waviness to the submicron level. Non-contact polishing is adopted, mechanical stress cannot be generated on the surface of the material, and introduction of related machining defects is avoided. Compared with a traditional polishing process, automatic machining can be achieved, the machining efficiency is high, and environmental pollution is small.

Description

technical field [0001] The invention relates to the field of laser polishing processing of metal material surface by powder-feeding additive manufacturing, in particular to an ultrafast-continuous laser asynchronous polishing process for powder-feeding additive manufacturing of metal surfaces. Background technique [0002] Ti-6Al-4V (TC4) titanium alloy has the advantages of high strength, low density, strong corrosion resistance, good heat resistance and good biocompatibility, and is widely used in aerospace, medicine, marine ships and other fields, especially It is suitable for key components such as human tissue, engine fans, blades, and aircraft structural parts, but it is one of the more difficult-to-process metal materials. Traditional machining is difficult to meet the increasing precision and complexity of TC4 titanium alloy parts, but Additive manufacturing technology is applied to the manufacture of TC4 titanium alloy parts, which can effectively solve its disadvan...

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Problems solved by technology

For example, the Chinese patent with application number 201410315813.X discloses a method for multiple laser polishing and strengthening of the surface of metal parts in additive manufacturing; and the Chinese patent with application number 201710244392.X discloses a single-step pulsed laser for metal surfaces In the polishing method, since the size of the molten pool at the spot is much smaller than the macroscopic protrusions that form the waviness during the laser polishing process, the single-step laser polishing in the above-mentioned patent cannot remove the waviness of the material surface well through the flow of liquid materials. The above-mentioned The objects of the patented laser polishing do not involve surface waviness, which is basically equivalent to only reducing the surface roughness of the plane, and it is difficult to better improve the surface quality of powder-feeding additive manufacturing metal parts

In addition, the Chinese patent with application number 201811546932.0 is also a composite asynchronous laser polishing process, but it is mainly aimed at ceramic materials, and the surface of ceramic materials does not involve surface waviness, and the patent only changes the surface roughness of ceramic materials from Ra1. About 8μm reduced to about Ra 0.6μm

Roughness belongs to the microscopic geometric shape error, and waviness belongs to the geometric error between microscopic and macroscopic. Since the size of the molten pool at the spot is much smaller than the macroscopic bulge that forms the waviness during the laser polishing process, single-step laser polishing cannot pass through the liquid material. The flow method can better remove the waviness of the material surface, but it is difficult to better improve the surface quality of powder-feeding additive manufacturing metal parts

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