Black Box Polarizing Keys
Nickel Silver polarizing keys used in electrical rack and panel connectors on aircraft flight data recorders better known as the “black box” won the award of distinction in the nonferrous category. The thin walled fragile part has an ultimate tensile strength of 34,000 psi (230 MPa), a yield strength of 20,000 psi (140 MPa), a 85 HRH hardness and 14% elongation
Density and weight control are critical to avoid tool failure and cracks in the “green” part. Close control of the sintering process is required to control ductility, distortion and eliminate the need for sizing. The parts must withstand a 500 connect/disconnect cycle test without measurable wear and are also tested for electrical conductivity. The net shape part requires no secondary operations and demonstrates a high degree of reliability. The keys can be found in almost every flight data recorder in commercial and military aircraft produced in the US.