Powder Metallurgical Products Cracking Is How One Thing?

1, inter-particle shift:
The bond between particles is mainly formed by plastic deformation and powder block movement. Under ideal conditions, the densification process is bidirectional, symmetric and synchronous. And there is no displacement of the intergranular edges. The displacement movement after the densification process prevents the intergranular bonding from forming and can destroy the bonds that have been formed in the early stages of formation.
2, high tension, shear force:
In the state of powder metallurgical embryos, cracks can occur if the shear force of the forming body is higher than the strength of the embryonic body of the forming body if the tension generated by the external or internal cause.
3, wrong material integration:
For a variety of reasons, metal powders use additives. For example, adding the right lubricant for mixing will increase compression and reduce demoulding. However, adding too much lubricant to mixed iron powders will inhibit intergranular bonding, adhesives, impurities, and even residual air. Can cause negative effects on bond formation.
4, abnormal plastic strain separation forming process:
The particles will undergo irreversible plastic deformation. In addition, recoverable plastic deformation will also occur. After the final forming stage, the related pressure will be reduced and eventually reduced to zero during the demolding process. The moment the forming pressure is released, the compression stress will be released. A somatic embryo will suddenly change from the plastic to the elastic stage. If the internal stress is greater than the limit of the somatic strength, cracks will occur.
The above is how the cracking of powder metallurgy products is introduced. The potential cracks in powder metallurgy products have been considered to have a huge impact and often become constraints in the application of powder metallurgy technology when producing complex shapes of parts.