Elctroless Nickel Plating On Quartz Glass And Its Influence On Diffusion Bonding

Quartz glass and quartz glass fiber are ideal window materials. In order to ensure the fuselage and window are well sealed,we usually use polymer as bonding materials. But polymer materials have problems of ageing in service. Make fuselage and window direct connection is the most ideal method, which not only increasing the service life of the windows but also improving the strength of the joint. In this paper, diffusion bonding was applied to join quartz glass and aluminum alloy with the layer of Ni-P alloy made by electroless plating as intermediate, and the interface of the sample is studied.In the preparation of Ni-P layer, a new Palladium-free method is applied to active the surface of glass. The activation solution includes 21 g/L NiSO4·6H2O, 11.5 g/L potassium sodium tartrate. Adjust pH to 7.8 with NaOH solution, then add little NaBH4 solution. Immerse the specimen in the reduce solution for 30 s and in the activation solution for 20 s, then dry quickly at low temperature to complete the process of activation. Chemical composition of electroless nickel plating bath: 32 ~ 34 g/L NiSO4·6H2O, 20 ~ 28 g/L Na3C6H5O7·2H2O, 30 g/L NaH2PO2·H2O, 25 ~ 30 g/L CH3COONa·3H2O, 15~20 ml/L C3H6O3,0.05 g/L KI, p H 4.5~5.5 and temperature 80~85℃.The structure of Ni-P plating is tight, smooth and amorphous, the content of P element is 14.40%.The diffusion behavior of nickel plating and quartz glass is studied. The optimum condition is: temperature 800~850℃, bonding pressure is 10~15 MPa, thickness of interlayer is about 0.5 μm, heat preservation is at least 30 min. There is a certain light transmittance after diffusion bonding of two slice of quartz glass. Visible light transmittance is more than 19.5%. Shear strength of the joint is 0.60 MPa. Shear fracture is mixed-mode fracture of parent material and interface.SPS technique is applied to join quartz glass and Al alloy. The influence of parameters variations on the microstructure and elemental diffusion of the jiont are characterized by SEM and EDS. The optimum condition time is: temperature 500℃, bonding pressure 4 MPa, diffusion time 5~10 min, thickness of interlayer is about 0.5μm. Al alloy, interlayer and quartz glass are closely connected, there is no cracks and holes in the joint.