Effect of magnesium silicate hydroxide on the friction behaviour of ductile cast iron pair and the self-repairing performance

Magnesium silicate hydroxide self-repairing material (0.5%, in mass) was dispersed into lubrication oil (Great Wall SJ10W-40). The anti-friction and anti-wear performance of the ductile cast iron friction pairs were examined by using a friction and wear tester. A comparison was made between SJ10W-40 lubrication oil with and without magnesium silicate hydroxide. The surface morphologies and elementary composition of grinding cracks of the sample were analyzed by using scanning electron microscopy and energy dispersive spectrometry. The results show that after magnesium silicate hydroxide self-repairing material is added to the lubrication oil, the friction coefficient decreases by 68.8%. There is a repairing layer whose material is different from the basic bulk material on the grinding cracks; in addition, Si, Mg, Al and other elements are deposited on the repairing layer. Magnesium silicate hydroxide self-repairing material possesses superior resistance to abrasion, excellent anti-friction properties and a self-repairing effect.