In a 2-year program sponsored by SJAC, an aqueous electroplating process using alkaline Zn-Ni with trivalent chromium post treatment is under evaluation for high strength steel for aircraft application as an alternative to cadmium. Commercial Zn-15%Ni rack/barrel plating solutions are basis for plating aircraft parts or fasteners. Brightener was reduced from the original formula to form porous plating that enables bake-out of hydrogen to avoid hydrogen embrittlement condition. Properties of the deposit, such as appearance, adhesion, un-scribed corrosion resistance, and galvanic corrosion resistance in contact with Al alloy, were evaluated. Coefficient of friction was compared with Cd plating by torque-tension measurements. Evaluation of the plating for scribed corrosion resistance, primer adhesion, etc. will continue in FY2007.
The Reflection Grating Spectrometer experiment (RGS) on the ESA corner stone X-Ray Multi-Mirror Mission (XMM) uses charge coupled devices (CCD) as detectors. Thermal requirements are the main driver for the layout of the detector housing. Parasitic heat inputs stem primarily from radiative coupling and from conduction over the structural support. Improvements in the design of the electro optical model (EOM) over the bread board model (BBM) resulted in a system that guarantees a CCD temperature of -130 °C at the end of the mission while not precluding the possibility to heat the detectors as high as +130°C which might be useful for annealing the CCDs.