Indirect forming method for preparing metal product

A molding method and metal technology, applied in the field of additive manufacturing, can solve the problems of low density and lack of metallurgical bonding.

Active Publication Date: 2021-01-26

HUNAN FARSOON HIGH TECH

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AI-Extracted Technical Summary

Problems solved by technology

The advantage of this process is that it has low requirements on equipment, metal prototypes do not need to be supported, and the production speed is fast. However, for better metal powder bonding, a large amount of polymer powder needs to be added, resulting in metal powder shape The metal p...

Abstract

The invention provides an indirect forming method for preparing a metal product. The indirect forming method comprises the following steps of uniformly mixing polymer powder and metal powder accordingto the volume ratio of (1-5): (95-99) to prepare metal composite powder materials; placing the metal composite powder materials in selective laser sintering equipment with an optical fiber laser as alight source for sintering, so that a metal prototype blank is prepared, wherein the sintering process specifically comprises the steps of laying polymer composite powder materials with the layer thickness of 0.1-0.2 mm, and preheating the metal composite powder materials to the set temperature which is 10DEG C-150 DEG C lower than the melting point of the polymer powder; and placing a metal prototype blank into an inert gas sintering furnace for degreasing and sintering to obtain the metal product. According to the indirect forming method, support is not needed, and rapid forming is achieved; the preparation time is short; and a prepared metal part is high in density and size precision.

Application Domain

Increasing energy efficiency

Technology Topic

Erbium lasersPolymer composites +6

Image

Examples

Experimental program(8)

Example Embodiment

[0022]Example one

[0023]Step 1: Add 2 parts of nylon 1212 powder with an average particle size of 60 μm and 98 parts of iron powder with an average particle size of 25 μm into the mixing equipment to perform physical mixing;

[0024]Step 2: Put the above-prepared composite powder of iron powder and nylon 1212 into a selective laser sintering equipment that uses a wavelength of 400nm as an optical fiber as the laser source. The maximum power range of the fiber laser is 500W, and the layer thickness is 0.15 mm, heat the composite powder of iron powder and nylon 1212 to a sintering temperature of 135°C, 53°C below the melting point of nylon 1212 powder, and then use a 300W sintered laser to melt the powder with a sintered line spacing of 0.3mm to prepare an iron prototype Sintered blanks.

[0025]Step 3: Debinding and sintering experiment Using an inert gas sintering furnace, put the iron prototype sintered blank into the sintering furnace, the debinding temperature of the first stage is 500℃, the holding time is 5h; the second stage sintering temperature is 1360℃, the holding time is 3h, inert Gas protection. Finally, it is cooled to obtain iron metal parts.

Example Embodiment

[0026]Example two

[0027]Step 1: Add 1 part of polylactic acid powder with an average particle diameter of 40 μm and 99 parts of copper powder with an average particle diameter of 1 μm into the stirring device, and perform physical mixing;

[0028]Step 2: Put the above-prepared composite powder of copper powder and polylactic acid into a selective laser sintering equipment that uses a wavelength of 500nm as the fiber as the laser source. The maximum power range of the fiber laser is 2000W, and the layer thickness is 0.1 mm, heat the composite powder of copper powder and polylactic acid to a sintering temperature of 100°C and 55°C below the melting point of the polylactic acid powder, and then use a sintered laser with a power of 2000W to melt the powder with a sintered line spacing of 0.5mm to prepare a copper prototype Sintered blanks.

[0029]Step 3: Debinding and sintering experiment Using an inert gas sintering furnace, put the copper prototype sintered blank into the sintering furnace, the debinding temperature of the first stage is 400℃, the holding time is 2h; the second stage of sintering temperature is 960℃, the holding time is 1h, inert Gas protection. Finally, cooling to obtain copper metal parts.

Example Embodiment

[0030]Example three

[0031]Step 1: Add 2 parts of polymethyl methacrylate powder with an average particle diameter of 50 μm and 98 parts of nickel powder with an average particle diameter of 10 μm into the stirring device to perform physical mixing;

[0032]Step 2: Put the above-prepared composite powder of nickel powder and polymethyl methacrylate into a selective laser sintering equipment that uses an optical fiber with a wavelength of 600nm as the laser source. The maximum power range of the fiber laser is 100W. The thickness of the layer is 0.12mm. The composite powder of nickel powder and polymethyl methacrylate is heated to a sintering temperature of 90°C, 60°C below the melting point of the polymethyl methacrylate powder, and then the powder is melted by a sintered laser with a power of 800W , The sintered line spacing is 0.4mm to prepare nickel prototype sintered blanks.

[0033]Step 3: Debinding and sintering experiment Using an inert gas sintering furnace, put the nickel prototype sintered blank into the sintering furnace, the first stage debinding temperature is 200℃, the holding time is 4h; the second stage sintering temperature is 1350℃, the holding time is 1h, inert Gas protection. Finally, it is cooled to obtain nickel metal parts.

PUM

Property	Measurement	Unit
Particle size	60.0	µm

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