Evaluating material performance between high current contact

The High Current Test Fixture (HiCTF) was developed to examine material response to repulsive forces generated between electrically conducting material pairs during short pulses of high current, similar to conditions experienced in EML applications. Based upon Holm contact theory with additional pre-load and pressure distribution parameters, this test fixture was designed to use a loading press to apply the pre-load to the test specimens while conducting current through the specimen contact interface. The fixture uses an aligned mechanical loading device to provide a preload across the contact interface of the specimen. The primary interests for the HiCTF are to investigate contact response sensitivity as a function of its degradation, impact of geometry variation, surface conditions, material pairing, pre-load, and contact integrity. Statistically based experimental designs have been constructed and analysis methodologies developed which incorporate likelihood ratio analysis and the Neyer method. The Neyer D-Optimal Design method, used in sensitivity testing of explosives, shows promise as an appropriate test method for HiCTF results, and will be used to provide sufficient information for comparisons and developmental thresholds. Results from HiCTF testing provide insight into electrical contact phenomenon and high current material response. This paper provides an overview of the High Current Test Fixture, its motivation, analysis methodology, results, observations, and lessons learned.