Study On Application Of Plasma Spraying Composite Ceramal Material In Cold Stamping Die Mould

In this paper the composites to reinforce surface of the die and mould have been fabricated by plasma spray. The composite combines the toughness of C45 steel matrix with the wear resistant of surface coating, in order to improve the useful life of die. The coating's microstructure and characteristic of friction and wear, technology, density, hardness, porosity, thermal conductivity et al. have also been investigated.1. The microstructure of coating is flattened particle pile up layer-cross together by hitting. The spraying distant, arc power et al. technology parameters have a great influence upon the characteristic of coating.2. Ni02 coating has a higher hardness. There are more pores and micro-cracks in the Al₂O₃+40%TiO₂ coating, but it is economical and practical, and easy to perform. Ni/Al2O3 coating has lower porosity, higher density and binding strength. As result of the difference melting point of composition, the composition distribution is not even in coating section.3. The wear resistant properties of coatings are better than that of the tool carbon steel T10, and the abrasive wear is low in wear against materials of ferroalloy. The wear resistant property of Ni02 coating is best in three coating, the wear rate of dry friction is less 6-15 times than that of T10, under lubricated friction less 2-3 order of magnitude than T10.4. The major wear mechanism of Ni02 coating is fatigue wear under lower stress, abrasive wear under higher stress. The Al₂O₃+40%TiO₂ ceramic coating wear by intercrystalline fracture and embrittlement.5. Because there are pores, micro-cracks, residual stress et al. defects in coating, the wear resistant properties of coating become worse under condition of shock load and inferior layer wear.6. The result indicated that the plasma spray composites coating on the surface of die and mould can remarkably raise its useful life in practical use.