Controlled Porosity and Lubrication in Powder Metallurgy Products

For applications requiring long term lubrication in hostile environments the controlled porous structure developed during the powder metallurgy process enables products to be made that are capable of absorbing up to 35% of selected fluids.
Self Lubricating Materials

When combined with specially selected materials such as graphite-based systems this unique capability enables self-lubrication to be used in ‘sealed for life’ systems.
Applications of Porous Materials

Current applications include ballpoint pens, bearings for industrial systems, micro components etc.
Filters

Controlled porosity is also employed in the manufacture of metal filters and diaphragms.
Advantages of Metal Filters over Ceramic Filters

They have the advantage over their ceramic counterparts

· of higher strength

· and resistance to mechanical and thermal shock.
How are Porous Materials and Filters Produced

The close control over the pore size and permeability is achieved by the use of powders having a narrow range of particle size.
Materials Used for Filters

Perhaps the most commonly used filter elements are made of bronze (89/11 Cu/Sn), and spherical powder are used. Other materials used include copper, nickel, bronze, stainless steel and 'Monel'.
Producing Porous Materials and Filters

The filter profile is formed by a loose packing of the powder in the mould and the inherently poor compressibility of spheres is no disadvantage.

Where products are required to have limited or localised porosity, conventional pressing is necessary and irregularly shaped particles are more suitable.
Applications of Metals filters

Metal filters are available in a wide range of materials including copper, nickel, bronze, stainless steel and 'Monel', and are widely used for the filtration of fuel oils, chemical solutions and emulsions.

They are also efficient in separating liquids of varying surface tension, and have been successfully applied to jet engine fuels, where water is removed at the same time as the fuel is filtered.

Similar devices are widely used for sound damping on air compressors and the likes.