Electroless Plating On Nano-sized Powders And Preparation Of Special Ceramics

Electroless Ni-P alloy plating on the nano alumina powder not only improves the weakness of the nano Alumina powder, which easily reunites, and enhances the powder's face activity, but also may combines the respective merit of substrate powder(Alumina) and metallic powder(Ni-P alloy), what is more, may develops some new traits. According to these purposes, during the electroless plating on the nano Alumina power, the paper mainly researches the craft of the former disposal, the basic formulation of the electroless nickel bath and idiographic scheme of electroless Ni-P alloy plating, sequentially elicit optimal the craft of the former disposal, the basic formulation of the electroless nickel bath and idiographic scheme of electroless Ni-P alloy plating. At the same time, the life span of the EN solution is also studied by a series of experiments, which firstly analyses the content of Ni²⁺by titration , secondly calculating the content of NiSO₄ by formula and accordingly constituting appropriate addition scheme. Making use of the experiments of the life span of the EN solution may ascertain the metal turn over (MTO) of the EN solution, the aim of experiments is a batch production of the powder. On this ground work, the black nano Alumina powder which is plated steer the diffraction of X ray and Scan the electric mirror examination analysis, As a result, the alumina dust is fully plated ,the plated lay includes the nickel as 9.32%, phosphorus as 2.32%, which present the crystal structure.Coating surfaces of Al₂O₃ powder by electroless method is believed to be an effective way to prevent powders from amalgamating and growing, avoiding heterogeneous distribution of low content additive when using conventional ball-milling method, to achieve synergistic toughening by interfacial modification.In this paper, with Ni-P coated Al₂O₃ powder as staring powders, sintered composites was obtained by non-pressing the mixture of powder. The mail contents are as follows: Non-pressing were carried out in the range of 1150℃to 1400℃with Ni content 9.32% and phosphorus content 2.32%. For comparison, the processing parameters of Al₂O₃/ Ni-P special ceramics were further optimized to be 1350℃and 40 min. Then the sample's properties were tested which included break flexibility density and abrasion. In comparison with Al₂O₃ composites, the break flexibility was improved from 3.0 MPa·m^1/2 to 6.91 MPa·m^1/2 by 130.3%; the highest density was 96.8%; the abrasion was ameliorated.