DoD Handbook- Materials and Process Requirements for Air Force Weapon Systems

4.1 Material selection.

The selection of materials and process shall be the result of design studies which shall be performed for each system. These studies shall include all the relevant parameters such as operational environments, performance, manufacturing capabilities, safety of fight structure, life cycle costs, and reliability and maintainability requirements as specified by the contract. These studies shall determine the acceptable initial ,flaw sizes, defects, and tolerances associated with the manufacturing processes, fabrication, and assembly. Inspection shall be capable of ensuring that the initial manufactured quality of the design meets the fatigue and damage tolerance requirements specified in the contract. Materials related considerations that shall form a part of the trade studies - include mechanical properties as identified in MIL-HDBK-5 other acceptable sources, stability under environmental conditions, corrosion susceptibility, fracture toughness, and crack growth (da/dn)under the service stresses. The service experience of established materials in similar applications shall also be considered.