Explanation

The volume fraction of pores in particles, compact and sintered body with pores. Pores include through holes connecting the surface of materials and closed holes enclosed in the materials. porosity is an important index of powder metallurgy. The higher the porosity of powder metallurgy materials, the lower the strength, toughness and other properties. The porosity of naturally stacked and compacted powder is 50% -70%, compact is 20% -80%, sintering porous materials is 40% -80%, sintering parts is less than 10%, and high density materials is 0.001% -2%. In addition to measuring porosity, porous materials also need to measure the through hole percentage, pore size and pore size distribution and other parameters. Such materials include selfoiling bearing, filter materials and separation materials, sweating materials, etc. porosity is usually obtained indirectly by measuring the density of materials with drainage method; The pore size and distribution were determined using bubble method and mercury intrusion method; The pore shape is observed under a microscope.

Classification