Damping and Microstructures in Aged Cu-Mn Based Alloys

摘要

An aged high damping alloy 53Cu 45Mn-2Al was studied both microstructurally by transmission electron microscopy (TEM) and microstructurally with two different damping measurement methods. In-situ heating and cooling observations were made with TEM in order to define the recently discovered flickering phenomenon associated with it's tweed microstructure. TEM studies were also made of an aged 53.6Cu-46.4Mn binary alloy. Damping measurements were obtained by a normalized bandwidth method applied to data from a resonant bar. This was used to determine (i) the aging condition for optimum damping, (ii) the subsequent trend of damping at room temperature for each aging condition, and (iii) the effect of an 8 HR storage at 100C on damping capacity. Damping measurements utilizing a free decay technique to determine log decrement were also used and compared to results from the normalized bandwidth method. Theses. (JES)