Energy-filtered imaging of precipitates in FeCuN alloys

摘要: The microstructures of a series model ferritic alloys are being characterized by transmission electron microscopy (TEM) techniques. have varying concentrations Cu (0 to 0.9 wt%), N (5 120 appm), and other solutes allow systematic study the effects various elements on embrittlement. first step in this process is characterization their as-received state: solution treated at 775 C for 17 h, quenched salt bath 450 180 s, subsequently air cooled. imaging portion initial complete; however, several questions about chemical content many precipitates remain unanswered. To affect precipitation hardening alloys, wt% alloy was annealed 550 times up 15 h. that form undergo phase change from bcc faulted fcc (9R) crystal structure when they 6 nm diameter. These been well conventional TEM techniques these alloys. However, smaller precipitates.