Composite binder for powder injection moulding and preparation and application method

Abstract

The invention discloses composite binder for powder injection moulding and a preparation and application method. The composite binder for powder injection moulding comprises raw materials including furfuryl alcohol, trimethylolpropane, polypropylene, o-hydroxybenzoic acid, polyacrylamide, palm wax, microcrystalline wax and epoxidized soybean oil and further comprises boric acid and water. The composite binder combining thermoplasticity and a thermosetting system is adopted, advantages of thermoplasticity and the thermosetting system are utilized, on one hand, the problems that conventional binder is excessively long in thermal degreasing time and low in production efficiency are solved, and the degreasing rate can reach 90% or above within 6 hours; on the other hand, the yield rate of a powder injection moulding product is raised, and quality of a finished product is improved.

Description

technical field [0001] The invention relates to the technical field of powder injection molding binders, in particular to a composite binder for powder injection molding, a preparation method and an application method. Background technique [0002] Powder injection molding (MIM for short) is a new type of powder metallurgy near-net molding technology formed by introducing modern plastic injection molding technology into the field of powder metallurgy. It has the advantages of one-time forming complex shape products, high dimensional accuracy, no need for mechanical processing or only minimal processing, low preparation cost, etc., and can form complex shapes, such as with horizontal holes, inclined holes, concave-convex surfaces, threads, thin Walls, ceramics and metal special-shaped parts that are difficult to machine, have a wide range of application prospects. As one of the four major methods of product production and processing, this technology is a high-tech that has d...

AI Technical Summary

Problems solved by technology

However, the existing adhesives are prone to swelling and cracking of large thickness samples during the solvent degreasing process.

If direct thermal degreasing is used, the process of thermal degreasing is very long, and the degreasing time is as long as dozens of hours, even up to hundreds of hours, which takes a long time, because the decomposition gas in the large thickness sample cannot escape smoothly, and produces Greater stress leads to defects such as bubbling and cracking, and the defects generated in the degreasing stage cannot be eliminated in the sintering stage; compared with thermal degreasing, the degreasing time of solvent degreasing is greatly shortened, but the green body is prone to swelling in organic solvents, which affects the green body. quality; on the one hand, the cost of catalytic degreasing is too high, on the other hand, catalytic degreasing under acidic conditions will corrode most of the metals, which limits its wide application in injection molding of metal powders with weak acid resistance