Effects of C-MoS₂-Fe₂O₃(Fe₃O₄) nano-lubricants on contact tip wear for non-copper coated solid wires

Aiming at the application of contact tip wear of non-copper coated solid wires in robot auto-welding, C-MoS₂-Fe₂O₃(Fe₃O₄) nano-composite lubricants were prepared on the surfaces of non-copper coated solid wires by a mechanical coating technique. The effects of C-MoS₂-Fe₂O₃(Fe₃O₄) lubricants proportion on the contact tip wear were investigated. The results demonstrate that lubricating property of C-Fe₃O₄ coatings outperformed lubricating property of C-Fe₂O₃ coatings. The anti-wear performance of the contact tip was enhanced with an addition of nano-MoS₂. The formation of protective self-repairing films at the rubbing interface of welding wires against the contact tip was attributed to the tribochemical reaction among lubricants. The tribofilm composition were FeO, MoS₂ and MoO₃ which lubricating properties are excellent. They can avoid direct contact of welding wires against the contact tip, thus the contact tip wear was inereasdel. Oxidative wear, abrasive wear and arc ablation were the primary mechanisms of the contact tip wear.