A Mechanism of Hot‐spots Formation at the Crack Tip of Al‐PTFE under Quasi‐static Compression. Issue 12 (3rd November 2017)

• Record Type: Journal Article
• Authors: Feng, Bin; Li, Yu‐chun; Hao, Hong; Wang, Huai‐xi; Hao, Yi‐fei; Fang, Xiang
• Is Part Of: Propellants, explosives, pyrotechnics. Volume 42:Issue 12(2017)
• Page Start: 1366
• Page End: 1372
• Publication Date: 2017-11-03
• Subjects: Reactive materials -- Al-PTFE -- Deformation and fracture -- Ignition; Propellants -- Periodicals; Explosives -- Periodicals; 662.2
• DOI: 10.1002/prep.201700106
• Languages: English
• ISSNs: 0721-3115

Abstract

Abstract: Generally, the Al‐PTFE (polytetrafluoroethylene) is thought to be inert under quasi‐static or static loads. However, it was found that Al‐PTFE would initiate under quasi‐static compression after a specific heat treatment procedure and the opening fracture plays a crucial role in the initiation. A unique micrographic fracture pattern which showed unstable crack propagation and a ductile‐to‐brittle transition was observed at openning cracks by SEM. Combining the observed microstructure with the stress distribution at the path of crack propagation derived from numerical simulation, a mechanism was proposed to explain the formation of "hot‐spots" at the crack tip. The temperature rise at the crack tip was estimated to be at least 612 °C, which is high enough to ignite the Al‐PTFE composite. Abstract :