Reasons for Impregnation of Powder Metallurgy Products

Powder metallurgy, as an advanced material preparation technology, is widely used in many fields such as automobiles, aerospace, and energy. The purpose of oil impregnation of powder metallurgy products is to improve their durability, wear resistance, and rust resistance.

1. Impregnation method
Impregnation is a commonly used oil impregnation method, which is suitable for small or medium-sized complex parts. The method is to completely immerse the powder metallurgy product in oil so that the surface fully absorbs the oil, and then remove it and dry it in hot air. The impregnation method allows the oil to penetrate into the pores of the product and improve its rust resistance. However, it should be noted that the impregnation method may not be able to completely remove the oil, so subsequent heat treatment or solvent cleaning is required.

2.Why do powder metallurgy products need to be impregnated?

Porosity In Powdered Metal Components

Cast components are impregnated to seal them against leaks. Powdered metal parts are impregnated to improve their material properties:

Improved Machining Properties  

Powder Metal components are notorious for their aggressive effect on cutting tools. Impregnation prior to machining effectively creates a more homogeneous surface that reduces potential for tool ‘chatter’. This can extend tool life by up to one hundred times

Surface Coating Pre-Treatment  

 The significant porosity in powder metal parts can harbour contaminates such as oil, acids or cleaning agents, from production processes. If left untreated, this can lead to subsequent surface treatments being damaged when the contaminants leach out to the surface. Impregnation effectively cleans and fills this porosity allowing a better quality surface treatment ensuring increased life expectancy.