Tribological behaviour of lotus-type porous cast iron

Tribological behaviours of lotus-type porous cast iron under oil lubrication were investigated with reciprocal motion friction testing equipment. Lotus-type porous cast iron was fabricated by unidirectional solidification in mixture gas of hydrogen and argon at high pressure up to 2.8 MPa. The porosity is controlled by partial pressures of hydrogen and argon during melting and solidification. The friction coefficient was improved by about 20%, and the seizure resistance was also improved by about double, and the abrasion resistance was decreased by about 20%, compared with that of non-porous cast iron. Thus, such improvement of wear resistance and seizure resistance of lotus cast iron may be attributed to the hardness and tribological behaviour of lotus-type porous cast iron.