Effect of Heat Treatment and Cyclic Strain Amplitude on the Damping Properties of Iron-Chromium Based Alloys

摘要

Fe-Cr-Al and Fe-Cr-Mo alloys are being studied for their high damping characteristics and possible utility to the Navy in the noise reduction and vibration control of shipboard machinery systems. This research studied the dependence of damping in these alloys on heat treatment and cyclic strain amplitude. Tensile specimens annealed at 900C and 1100C were subjected to cyclic axial loading at low strain levels on an MTS mechanical testing system, generating load-displacement hysteresis loops at various frequencies. These hysteresis loops were analyzed to determine the damping response at various levels of loading. Damping capacity is found to be dependent on both strain amplitude and frequency. A comparison is made between these results and previous work which evaluated the strain dependence of damping in these alloys using more conventional experimental methods. Keywords: Cyclic strain amplitude; Damping properties; Iron-Chromium based alloys; Heat treatment; Molybdenum; Aluminum; Theses. (jes)