A Test of Noble Metal Slip-Ring Alloys for Use in Inertial Guidance Platforms

Lubricated slip-ring contact materials were life-tested in a nitrogen atmosphere and in a multichemical atmosphere that simulated the gases in an inertial guidance platform. The test mode was one that maximized the effects of debris accumulations and the generation of resistive films on infrequently wiped surfaces. The contacts that were lubricated with a four-ring polyphenyl ether had lower noise than ones lubricated with a blend of diester and chlorofiuorocarbon oils. The alloys grouped in decreasing order of performance as sliding contacts for inertial guidance platforms are as follows: Group I-ASTM B477; 4 Ni, Au; 1 Ni, Au electrodeposit; Group II-ASTM B541; 10 Cd, Au; Group III-54.5 Au, 37.5 Ag, 4 Cd, 4 In.