Which method is used to create porous metal bearings?

The method used to create porous metal bearings is sintering. Sintering involves compacting fine metal powders into a desired shape and then heating them below their melting point. This process allows the particles to bond together, forming a solid structure while maintaining a certain level of porosity, which is crucial for applications in bearings where lubrication retention is essential.

Sintered bearings can hold lubricants within their pores, reducing friction and wear when in operation. This unique property makes them particularly suitable for applications in various machinery where low maintenance and longevity are desired.

The other methods mentioned, such as blow moulding, injection moulding, and transfer moulding, are typically used for plastics and other materials where a different fabrication process is required. They do not achieve the specific porous characteristics needed for metal bearings, making them unsuitable for this application.