Detailed explanation of metal powder injection for molding technology

First of all, the metal powder injection molding is to mix the solid powder and organic bonding evenly. After the particles are made of the heating and plasticizer, the forming machine is used to inject in the mold cavity. The bonding agent was removed, and the final product was finally obtained by sintering degradation.

The method of skipping fat in metal powder injection is: heat decomposition, solvents, catalytic dehydration, etc. Among them, the size of the product produced after catalytic abandonment is high, and our company uses catalytic skimming.

Taking a polydehyde (POM) adhesive as an example, the sedimentation process is divided into three stages: front rinse, abandonment and back rinse.

Pre -rinse stage: Because the dehydration product of the metal powder injection of raw embryos will react with the oxygen, the air in the furnace cavity needs to be diluted before the abandoned, so that the internal oxygen content can reach the safety value. In the front flushing phase, the furnace cavity, flue and nitrogen pipes will be performed, and the furnace fan will be initiated at the same time to transport nitrogen to the furnace.

Discard stage: It refers to the process of decomposing the adhesive (polydehyde) into formaldehyde in the setting temperature at the set temperature. The furnace is in the preservation state, the nitric acid pump is started, and nitric acid is injected into the furnace. In an acidic atmosphere, the decomposition response rate of polydehyde is accelerated.

Relaxation phase: After the abandoned phase is over, nitrogen starts to fill the stove cavity, and discharge the formaldehyde and nitric acid generated by the dehydration phase in the furnace. Formaldehyde and nitric acid will be heated in the tube. Eventually, only carbon dioxide, water vapor and nitric oxide gases are expelled from the outside. These are gas that constitutes air, which meets environmental protection requirements.

The metal powder with a catalytic skilled dysfunction is injected into a raw embryonic dehydration rate of up to 90%and turned into ash. The next stage is to enter the sintering furnace for sintering.