What Are The Degreasing Processes of The MIM Degreasing Sintering Furnace?

The degreasing processes of MIM degreasing sintering furnace mainly include solvent degreasing, thermal degreasing, catalytic degreasing, etc., as follows:

· Solvent degreasing: Utilizing organic solvents to remove the solvent portion from the binder. It is usually carried out at a certain temperature, which can accelerate the degreasing rate. This method can remove most of the binder, making the green body have a certain porosity and creating conditions for subsequent sintering. However, after solvent degreasing, it is generally necessary to combine methods such as thermal degreasing to remove the remaining binder.

· Thermal degreasing: It is removed by heating thermoplastic or thermosetting binders to decompose and volatilize. Hot degreasing is usually carried out in a protective atmosphere, such as a nitrogen atmosphere, to prevent the oxidation of metal powders. This method has a relatively simple degreasing process, but the heating rate needs to be strictly controlled; otherwise, it is easy to cause problems such as deformation and cracking of the green body.

· Catalytic degreasing: Utilizing a catalyst to accelerate the degreasing process, nitric acid and the like are commonly used as catalysts. For instance, the Catamold® catalytic degreasing method takes advantage of the property of polyaldehyde resin to depolymerize into formaldehyde gas in an acidic atmosphere to remove most of the binder, and is suitable for binders in polyaldehyde resin systems. This method has a fast degreasing speed, can effectively reduce degreasing defects, and avoid problems such as product deformation and difficulty in controlling dimensional accuracy.

Two-step degreasing: Combining solvent degreasing and thermal degreasing, first use solvents to remove most of the binder, reducing the binder content in the green body and giving it a certain pore structure, and then use thermal degreasing to remove the remaining binder. This method can effectively prevent problems such as blank deformation, micro-cracks and low density, and improve the degreasing quality and product qualification rate.

· Vacuum degreasing: Degreasing carried out in a vacuum can reduce the limitation of gas flow, which helps to remove organic matter more thoroughly and also prevents powder oxidation. A vacuum environment can lower the boiling point of the adhesive, making it easier to volatilize and remove, and can also prevent oxidation reactions, which is conducive to ensuring product quality.

· Ultrasonic-assisted degreasing: It is usually used in the solvent degreasing process. By taking advantage of the effect of ultrasonic waves, it enhances the penetration ability of the solvent into the binder, improves the degreasing efficiency, and makes the degreasing more uniform and thorough. It is especially suitable for degreasing complex-shaped or low-porosity blanks.

Microwave-assisted degreasing: Utilizing microwave energy to accelerate the degreasing process, microwaves can cause the binder to rapidly absorb energy and heat up, promoting the decomposition or evaporation of the binder, thereby increasing the degreasing rate. Moreover, it can achieve uniform heating inside the green body, reducing issues such as deformation during the degreasing process.