Plastic-based binding agent and method for preparing powder injection molding green bodies through same

Abstract

The invention discloses a plastic-based binding agent and a method for preparing powder injection molding green bodies through the same. The plastic-based binding agent is prepared from, by weight, 75-88% of polyoxymethylene, 4-10% of modified polylactic resin, 3-10% of microcrystalline wax, 2-8% of pentaerythritol stearate, 1-10% of sebacic acid dibutyl ester and 0.5-2% of an antioxidant. The method for preparing powder injection molding green bodies through the plastic-based binding agent comprises the steps that metal or ceramic powder is preheated and stirred; the binding agent is added and banbury mixing is performed; after banbury mixing is performed, extrusion and pelleting are performed to obtain granular feed; injection molding of the granular feed is performed; green bodies obtained through injection molding are catalyzed and degreased through nitric acid, and the powder injection molding degreased green bodies are obtained. The adopted plastic-based binding agent is low in viscosity and good in flowing performance during injection molding, and the good mold filling capacity and the good green body stability are achieved; the plastic-based binding agent can be widely applied to the powder injection molding industry, and the plastic-based binding agent is particularly applicable to production of parts with the large draw ratio, small wall thickness, micro size and complex three-dimensional shapes.

Description

technical field [0001] The invention relates to a plastic-based binder for powder injection molding and a method for preparing green body thereof, which can be widely used in the powder injection molding industry, especially suitable for large aspect ratio, thin wall thickness, small size and three-dimensional The production of parts with complex shapes belongs to the technical field of powder injection molding. Background technique [0002] Powder injection molding is the use of polymer organic matter as a binder, making full use of its melting and rheological properties when heated to a certain temperature, similar to injection plastics, to form a mixture of powder and binder into various desired shapes Then use chemical or thermal decomposition methods to remove the binder in the formed blank, and finally obtain the final product through sintering and densification and necessary subsequent processing procedures. This technology has unique advantages in preparing high-pre...

AI Technical Summary

Problems solved by technology

This kind of binder system formulation is often used for metal injection molding of conventional size, but it has poor fluidity in the manufacture of miniaturized, miniaturized and profiled metal and ceramic products, especially for large aspect ratio and wall Products such as thickness, small size and complex three-dimensional shape have defects such as insufficient filling, flow marks, weld marks and other defects during injection, which directly restrict the mass production of powder injection molding products

Images