#################################################### # Pete Jemian # requesting 6 days, at minimum=3 days # beamline 33ID, "USAXS study of precipitation in Ni-based superalloy" #################################################### # top:/home/www/beamtime-requests/req00424.txt # UNICAT Member Beam Time Request #424 # created Tue Jun 03 11:34:23 CDT 2003 #################################################### beamline: 33ID collaboration: No collaborator_Pete: ON contact: jemian@uiuc.edu days: 6 description: We propose to investigate the precipitate populations in the first series of Ni-based superalloy by USAXS. Then, if feasible, ASAXS to separate population distributions. Attached is brief outline of overall research program. Structure-Property Relationships in High Temperature Alloys P.I. Rosario Gerhardt (funded by DOE-BES) High temperature alloys such as nickel base super-alloys are used in gas turbine engines. These materials are characterized by a microstructure that includes a fine dispersion of precipitates coherently distributed throughout the grains. When the material is polycrystalline, it also contains carbides located at the grain boundaries. Since these materials are used at high temperatures for long periods of time and cycled in temperature and mechanical loading, they can experience dramatic changes in mechanical properties caused by a changing concentration, size and distribution of the precipitates. In this project we are utilizing impedance and dielectric spectroscopy as a non-destructive technique for evaluating microstructural evolution in binary nickel base alloys. The first part of the research will focus on nickel base superalloys that will be subjected to different aging treatments to obtain different gamma prime precipitate populations (size, shape and distribution). These will serve as the baseline for extended high temperature exposure studies that will assess how the gamma prime population changes with different time and temperature exposures. Preliminary electrical data obtained is encouraging because it suggests that the precipitate population affects the impedance in a systematic way. The effect of the carbides will be assessed after the effects of the changes in the gamma prime population have been determined. In order to establish more quantitative correlations with the microstructural features present in the material, all samples tested will be characterized using SEM, AFM, TEM and USAXS. High resolution SEM can be used to identify the shape and distribution of precipitates and other microstructural features. AFM can be used to image the topography and electrical response of individual features simultaneously, while TEM can provide information about any changes in the composition, roughness and thickness of interfaces between phases. USAXS will be used because it is the only technique that can quantify the precipitate population in a statistically significant way. With the recent development of USAXS imaging, it will be possible to do both quantification as well as imaging of the same samples. Collaborations with Dr. Peter Jemian of UNICAT and Dr. Gabrielle Long of NIST are in progress. Future programs will also assess the effects of mechanical loading at different stages in the thermal, creep and low cycle fatigue cycles that these materials are subjected to. Research programs that will focus on what effect mechanical deformation has on the electrical response of these materials are currently under development and proposals will be submitted for consideration by NSF and/or AFOSR. equipment_required: USAXS experiment: USAXS study of precipitation in Ni-based superalloy foreign_nationals: hazards: no hazards sample prep will be done offsite samples are thin metal foils of Ni-based superalloy minimumdays: 3 name: Pete Jemian new_request: ON nonmembers: Rosario Gerhardt, Georgia Tech unacceptable_dates: request unscheduled beam time on 33ID from July 30 to August 5, 2003 z34ID_details: z34ID_parasitic: yes z34ID_taper: 33ID #REMOTE_HOST: zrh.uni.aps.anl.gov #REMOTE_ADDR: 164.54.216.36 #CONTENT_LENGTH: 3940 #HTTP_REFERER: http://www.uni.aps.anl.gov/unireq.htm #HTTP_USER_AGENT: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.1) Gecko/20020826