Papers by Author: Chang Hong Li

Abstract: TiO2-Ni wear-resistant film on metal surface is manufactured by electroless composite plating. TiO2 content in the film depends on the concentration of TiO2 particle in the plating liquid. The optimal TiO2 content in the plating liquid is 15-20g/l. TiO2 content in the film is 5-8%. When TiO2-Ni composite film is treated at 200°C, its hardness increases with the prolonging of heat-treatment time. After 10 hours heat-treatment at 200°C, the hardness increases from HV 750 kg/mm2 to HV 1300 kg/mm2.

Abstract: Copper film was plated on Al2O3 ceramic powder in Al2O3 ceramic with copper matrix. The influence of copper film plated on Al2O3 ceramic powder to friction coefficient and amount of wear has been studied in this paper. Variance analysis shows that copper film on Al2O3 ceramic powder does not have significance influence to friction coefficient, but has significance influence to amount of wear of Al2O3 ceramic with copper matrix. Amount of wear of Al2O3 ceramic with copper matrix decreases with the increase of copper film plated on Al2O3 ceramic powder initially. When the copper film plated is beyond 47%, The amount of wear reaches a stable volume, and almost does not reduce again with the increase of the copper film plated on Al2O3 ceramic powder. To Al2O3 ceramic with copper matrix in this paper, the optimum copper film plated is 47%.

Abstract: Graphite is introduced into Al2O3 ceramic with copper matrix. The influence of graphite content to friction factor and wear and tear of Al2O3 ceramic with copper matrix has been studied in this paper. Friction factor of ceramic with copper matrix decreases with the increase of graphite content at first. After graphite content exceeds more than 3%, friction factor stops reduction. Wear and tear decrease with the increase of graphite content from the beginning. After graphite content surpasses more than 3%, it increases instead with the increase of graphite content. When graphite content is 3%, Wear and tear locates the lowest point. Solid lubrication film formed by graphite on the friction surface is the cause that makes friction factor drop.