Water-soluble salt core type metal powder injection molding technology

Abstract

The invention provides a water-soluble salt core type metal powder injection molding technology and relates to the technical field of metal powder injection molding. The technology comprises the steps of mixing, water-soluble salt core preparing, mold core inlaying and mold clamping, injection molding, core-removing drying, degreasing and sintering. According to the technology, a fused and poured water-soluble salt core forms a part cavity and can be dissolved and removed through clean tap water at indoor temperature, the removal time is short, the safety is high, the environmental friendliness is high, and the potential problems of production insecurity, environmental pollution and strength reduction of green bodies caused by polymer core removal can be effectively solved. Part products manufactured through the technology are uniform in internal structure, high in compactness, high in surface smoothness, high in dimensional precision and stable in quality, a great deal of time and cost are saved for volume production of small and precision parts provided with closed or complicated cavity structures and made of various metal materials, the economic benefit is good, and the application prospect is good.

Description

technical field

[0001] The invention relates to the technical field of metal powder injection molding, in particular to a water-soluble salt core metal powder injection molding process for parts with complex inner cavity structures. Background technique

[0002] Metal injection molding, as a near-net-shaping technology for manufacturing high-quality precision parts, has incomparable advantages over conventional powder metallurgy and machining methods. It is used in the batch manufacturing of small parts with complex shapes, especially those that require multiple assemblies using other production processes. Or the parts that can only be realized in the forming process, it shows huge advantages in technology and cost. The process steps are: firstly, the metal powder and the binder are uniformly mixed in the internal mixer, and then the crushed granular feed is injected into the injection machine to form a green body with a certain strength, and then through various This degre...

Examples

Embodiment 1

[0029] The steps of this method are as follows:

[0030] ① Mixing: Put the metal powder and organic binder into the internal mixer at a ratio of 8:1. The organic binder is polyethylene, polypropylene, polyoxymethylene, polystyrene, vinyl acetate, paraffin, beeswax one or more of them. In order to reduce the oxidation tendency of the metal powder and at the same time suppress the evaporation of the organic binder, the metal powder and the organic binder are kept at a temperature of 180°C in a closed environment and stirred for 40 minutes to make the metal powder and the binder Mix well to prepare granular feed suitable for injection.

[0031] The shape of the material used in injection molding is generally cylindrical or square. As a specific implementation, the material used in this embodiment is cylindrical.

[0032] ②Preparation of water-soluble salt core: mix NaCl powder, Na 2 SO 4 Powder and CaCl 2 The powder is mixed evenly according to the molar ratio of 6.5:2.5:1, ...

Embodiment 2

[0043] The steps of this method are as follows:

[0044] ① Mixing: Put the metal powder and organic binder into the internal mixer at a ratio of 10:1.1. The organic binder is polyethylene, polypropylene, polyoxymethylene, polystyrene, vinyl acetate, paraffin, beeswax one or more of them. In order to reduce the oxidation tendency of the metal powder and at the same time suppress the evaporation of the organic binder, the metal powder and the organic binder are kept at a temperature of 200°C in a closed environment and stirred for 35 minutes to make the metal powder and the organic binder The agent is mixed evenly to make a granular feed suitable for injection.

[0045] The shape of the material used in injection molding is generally cylindrical or square. As a specific implementation, the material used in this embodiment is cylindrical.

[0046] ②Preparation of water-soluble salt core: mix NaCl powder, Na 2 CO 3 Powder and KCl powder are mixed uniformly according to the mol...

Embodiment 3

[0057] The steps of this method are as follows:

[0058] ① Mixing: Put metal powder and organic binder into the internal mixer at a ratio of 88:12. The organic binder is polyethylene, polypropylene, polyoxymethylene, polystyrene, vinyl acetate, paraffin, beeswax one or more of them. In order to reduce the oxidation tendency of the metal powder and at the same time suppress the evaporation of the organic binder, the metal powder and the organic binder are kept at a temperature of 220°C in a closed environment and stirred for 35 minutes to make the metal powder and the organic binder The agent is mixed evenly to make a granular feed suitable for injection.

[0059] The shape of the material used in injection molding is generally cylindrical or square. As a specific implementation, the material used in this embodiment is cylindrical.

[0060] ②Preparation of water-soluble salt core: mix NaCl powder, Na 2 CO 3 Powder and KCl powder are mixed uniformly according to the molar ra...

technical field

[0001] The invention relates to the technical field of metal powder injection molding, in particular to a water-soluble salt core metal powder injection molding process for parts with complex inner cavity structures. Background technique

[0002] Metal injection molding, as a near-net-shaping technology for manufacturing high-quality precision parts, has incomparable advantages over conventional powder metallurgy and machining methods. It is used in the batch manufacturing of small parts with complex shapes, especially those that require multiple assemblies using other production processes. Or the parts that can only be realized in the forming process, it shows huge advantages in technology and cost. The process steps are: firstly, the metal powder and the binder are uniformly mixed in the internal mixer, and then the crushed granular feed is injected into the injection machine to form a green body with a certain strength, and then through various This degre...

Examples

Embodiment 1

[0029] The steps of this method are as follows:

[0030] ① Mixing: Put the metal powder and organic binder into the internal mixer at a ratio of 8:1. The organic binder is polyethylene, polypropylene, polyoxymethylene, polystyrene, vinyl acetate, paraffin, beeswax one or more of them. In order to reduce the oxidation tendency of the metal powder and at the same time suppress the evaporation of the organic binder, the metal powder and the organic binder are kept at a temperature of 180°C in a closed environment and stirred for 40 minutes to make the metal powder and the binder Mix well to prepare granular feed suitable for injection.

[0031] The shape of the material used in injection molding is generally cylindrical or square. As a specific implementation, the material used in this embodiment is cylindrical.

[0032] ②Preparation of water-soluble salt core: mix NaCl powder, Na 2 SO 4 Powder and CaCl 2 The powder is mixed evenly according to the molar ratio of 6.5:2.5:1, ...

Embodiment 2

[0043] The steps of this method are as follows:

[0044] ① Mixing: Put the metal powder and organic binder into the internal mixer at a ratio of 10:1.1. The organic binder is polyethylene, polypropylene, polyoxymethylene, polystyrene, vinyl acetate, paraffin, beeswax one or more of them. In order to reduce the oxidation tendency of the metal powder and at the same time suppress the evaporation of the organic binder, the metal powder and the organic binder are kept at a temperature of 200°C in a closed environment and stirred for 35 minutes to make the metal powder and the organic binder The agent is mixed evenly to make a granular feed suitable for injection.

[0045] The shape of the material used in injection molding is generally cylindrical or square. As a specific implementation, the material used in this embodiment is cylindrical.

[0046] ②Preparation of water-soluble salt core: mix NaCl powder, Na 2 CO 3 Powder and KCl powder are mixed uniformly according to the mol...

Embodiment 3

[0057] The steps of this method are as follows:

[0058] ① Mixing: Put metal powder and organic binder into the internal mixer at a ratio of 88:12. The organic binder is polyethylene, polypropylene, polyoxymethylene, polystyrene, vinyl acetate, paraffin, beeswax one or more of them. In order to reduce the oxidation tendency of the metal powder and at the same time suppress the evaporation of the organic binder, the metal powder and the organic binder are kept at a temperature of 220°C in a closed environment and stirred for 35 minutes to make the metal powder and the organic binder The agent is mixed evenly to make a granular feed suitable for injection.

[0059] The shape of the material used in injection molding is generally cylindrical or square. As a specific implementation, the material used in this embodiment is cylindrical.

[0060] ②Preparation of water-soluble salt core: mix NaCl powder, Na 2 CO 3 Powder and KCl powder are mixed uniformly according to the molar ra...