Si
3N
4 ceramics are often used as sliding parts in severe environments because of their properties of high hardness, light weight and superior abrasion resistance. Oil lubricant is applied to minimize their friction and wear. In addition to or instead of oil lubricant, lipophilic and self-lubricating materials and processes are being explored.
In this study, Fe
3O
4 and Mo were added to Si
3N
4 to enhance the lipophilic properties and the abrasion resistance, while retaining strength. As a result, after adding Fe
3O
4 or Mo, the hardness, bending strength and density of Si
3N
4 ceramics decreased, while the lipophilic properties and abrasion resistance were enhanced. The lipophilic properties and abrasion resistance of Si
3N
4 ceramics after adding Fe
3O
4 and Mo were enhanced by either porosity or Fe
3O
4 on the material surface. The contact angle of macro-oil droplets became lower after adding Fe
3O
4, while the contact angle of micro-oil droplets remained almost the same.
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