Self-Lubricated Sintered Bearings… All PROS, no CONS?
In a nutshell… Sintered bronze oil-impregnated bearings are porous metallic components made of bronze or iron impregnated with lubricating oil. The oil contained in the porosity provides constant lubrication between bearing and shaft, so the system requires no external lubricant.
These types of plain bearings have been around for the past 90 years and are widely used in many different types of applications worldwide.
Main advantages of sintered bronze bearings include:
Self-lubricating, maintenance-free, high sliding velocities, low friction coefficient, low-noise running.
Here are several steps involved in how the powdered metal process works, but the result can be a low-cost, high-quality powdered metal part. Listed below is the typical sintered metal casting process in order:
Blending – This is the process of combining metal powders or alloys with lubricants to produce a homogeneous mix.
Briquetting – This process is where metal powders or alloys are compressed while restricted in a die, at pressures as low as 10 to 45 tons per square inch.
Sintering – Here each particle bonds into a mass. The parts are heated in a protective atmosphere furnace to a high relative temperature below the melting point of the particular metal or alloy.
Repressing – This is the final pressing of a sintered metal part to obtain proper size and physical properties.
Infiltrating – This process fills the pores of a sintered metal part with a metal or alloy of a lower melting point.
Impregnation – This process fills the pores of a sintered metal part with a lubricant.
Heat Treating – This is the heating of a sintered metal part in a protective atmosphere and then oil quenching the part. The results are usually improved strength and hardness.
Machining – If required powdered metal parts can be machined to obtain the desired shape before or after heat-treating is completed.