Launch Lock Mechanism Design Fault Tree Use and Coatings Study

Characteristics of a design process of a launch lock (LL) mechanism are described. This process began with generation of data that proved a previous design would not perform its function reliably. The redesign was then accomplished through the use of fault tree analysis, which helped make a better connection between requirements and actual failure scenarios. FEA modeling techniques for proper stiffness verification through testing are explored. Proto-type testing revealed that coatings at a volatile spherical joint interface became the primary area of concern as multiple configurations failed. Boron Carbide, bare AM355 to Ti6Al4V with Braycote 600EF, Tiodize, Diamond-like nano-carbon (DLN), and improperly configured coatings of MoS2 and TiCN were all shown to have unacceptable particle generation. TiCN and MoS2 doped with SbO3 and Au were shown to meet cleanliness requirements once coating parameters were properly controlled.