Reliability testing and analysis of safing and arming devices for army fuzes

Abstract

To address the lack of micro-electro-mechanical systems (MEMS) reliability data as well as a standardized methodology for assessing reliability, the Metallic Materials Technology Branch at Picatinny Arsenal has initiated a MEMS Reliability Assessment Program. This lack of data has been identified as a barrier to the utilization the MEMS in DOD systems. Of particular concern are the impacts of long-term storage and environmental exposure on the reliability of devices. Specific objectives of the Metallic Materials Technology Branch (MMTB) program include: • Identify MEMS devices to be utilized in weapon systems. • Determine the relevant categories of MEMS materials, technologies and designs in these applications • Assess the operational environments in which the military MEMS device may be utilized. • Analyze the compatibility of MEMS devices with energetic and other hazardous materials. • Identify physics of failure, failure mechanisms and failure rates. • Develop accelerated test protocols for assessing the reliability of MEMS according to the categories. • Develop of reliability models for these devices. • Conduct testing and modeling on representative devices of interest to Army and DoD. • Develop of a methodology and capability for conducting independent assessments of reliability that cannot be obtained from private industry. In support of this effort, some testing has been performed on prototype mechanical Safety and Arming (S&A) devices for the 25-mm XM25 Air Burst Weapon. The objective is to test the S&A as a representative device for the identification of potential failure modes and effects for devices of the same class. Information derived from this testing will be used to develop standardized test protocols, formulate reliability models and establish design criteria and to identify critical parameters in support of the S&A development effort. To date, Environmental Stress Screening (ESS) tests have been performed on samples of the device. Along with the ESS testing, a failure modes and effects analysis has been developed and reliability modeling is under way.