#################################################### # Prof. Waltraud M. Kriven # requesting 6 days, at minimum=4 days # beamline 33BM, High Temperature X-ray Diffraction Investigations of Kinetics of Crystallization and Crystal Size growth in Oxide Ceramic Materials # instrument 33BM-C fourc #################################################### # top:/home/www/beamtime-requests/req00993.txt # UNICAT Member Beam Time Request #993 # Orginal UNICAT Member Beam Time Request #961 # created Mon May 01 15:59:41 CDT 2006 #################################################### apsrun: 2006-02 beamline: 33BM collaboration: Yes collaborator_Jenia: ON collaborator_Paul: ON contact: kriven@uiuc.edu days: 6 description: In-depth understanding of the structure-property relationships is necessary to tailor ceramic materials for application in suitable areas. For this objective it is important to evaluate the properties of materials in the anticipated working environment. In-situ high temperature investigations to understand structure changes in ceramics are still a challenge. The primary objective of this research is to study the kinetics of crystallization behavior and crystal size growth in selected oxide ceramics, by high temperature x-ray diffraction (up to 2000C in air). We have developed a 2-dimensional (2-D) Curved Image Plate Detector (CIPD) in collaboration with scientists at the Deutsche Elektronen Synchotron Laboratorium (DESY) in Hamburg, Germany and at the APS/XOR/UNICAT beam line. The detector has been configured for use with the Huber 4-circle diffractometer at 33BM-C beamline. In addition, we have also developed a quadrupole lamp furnace (QLF)) and demonstrated the feasibility of conducting in-situ high temperature x-ray diffraction (HTXRD) experiments up to 2000 C in air. The coupling together of CIP detector and QLF offers the unique advantage of conducting rapid HTXRD studies to study kinetics of reactions in ceramic oxide systems. The CIP detector affords a resolution more than 0.007, and enables acquisition of XRD patterns in less than 20 seconds. The proposed research will utilize the QLF together with the CIP detector to understand the crystallization kinetics of mullite (3Al2O3.2SiO2) and leucite 4SiO2:Al2O3:K2O:12H2O ) ceramic phases. While amorphous 3:2 mullite will be synthesized by steric entrapment method, the amorphous leucite will be prepared by geopolymerization. The crystallization behavior of these amorphous powders will also be studied using different thermal analysis methods such as DSC/DTA besides the proposed HTXRD investigations. HTXRD scans at isothermal conditions for at least 7 different suitable temperatures will be acquired to evaluate the extent of crystalline phase formation. Datasets will be analyzed using Rietveld method for pattern fitting. T-T-T curves will be constructed to determine the activation energy of crystallization for leucite and mullite phases. In case of mullite, the crystallization behavior will also be studied as a function of the TiO2 dopant concentration. It has been widely observed that TiO2 promotes the preferential growth along the c-axis of mullite, however, the mechanism and its progress is not completely understood. The grain growth behavior of the crystalline TiO2-doped mullite phase will also be studied to determine activation energy of grain growth along different crystallographic directions. For these studies, the HTXRD datasets will be analyzed by pattern decomposition methods as differential grain growth behavior is anticipated as a function of crystallographic direction. Leucite-type ceramics (MAlSi2O6, where M is an alkali, K+, Cs+) tolerate a high degree of cationic substitution, and can also incorporate additional silica. We have shown that it is possible to synthesize amorphous precursors to such aluminosilicate phases by a novel geopolymeric route in near-net-shapes. This route is every promising as it is performed at room temperatures. However, the conversion of the amorphous to the crystalline leucite phase is not completely understood. We anticipate that the proposed study will enable a better understanding of the process. This work is a subset of the PIs ongoing research initiative in developing smart composites with tailorable thermal expansion, which is achieved by cationic substitution and silica additions in leucite and leucite type ceramics, by the geopolymeric route. The proposed work is important because it does basic research to understand behavior of oxide ceramics particularly at elevated temperatures. Moreover, it also forms the heart of the dissertation of two graduate students at UIUC who are pursuing their Ph.D. degrees in Materials Science and Engineering. We anticipate that results from the proposed research will have a profound effect on guiding the design and fabrication of high temperature actuators, sensors, shape memory materials, tough, and strong ceramic matrix composites which extend the application range of high temperature applications. equipment_required: None experiment: High Temperature X-ray Diffraction Investigations of Kinetics of Crystallization and Crystal Size growth in Oxide Ceramic Materials foreign_nationals: Prof. Waltraud M. Kriven (citizen of Australia) Dr. Pankaj Sarin (citizen of India) Wonki Yoon (citizen of Republic of Korea (South Korea)) hazards: The instrumentation intended for use during the proposed experiments has been earlier used at the 33-BM, and was last evaluated during February 2006. We will be incorporating the three suggested necessary changes - (a) Sticker to label the location of 0.5 amp fuse inside the temperature controller unit, (b) change of socket for output of power to lamp furnace, and (c) securing the of temperature control fuse (inside the controller unit) and (c) securing of any loose wires. Besides that the following text summarizes the instrumentation and the experimental procedure. The HTXRD experiment uses a small, water-cooled, four-lamp furnace capable of 2000 deg C. There are no apparent hazards other than those normally associated with using high energy synchrotron radiation. The samples of the following types will be studied (a) small sintered rods (300-400 microns in diameter and < 2.5 cm in length), or (b) thin sintered plates (4mm (L) X 4mm (H) X 250 microns (W)), or (c) small quantities of ceramic oxide powders (<0.1gm) mounted in quartz capillaries. These samples will be studied in transmission mode, with the x-rays passing through the sample. All the samples are non-toxic. Similar experiments have been conducted at UNICAT 33BM-C before. The design and operation of the CIPD has been discussed in detail with the UNICAT scientists, considering all the safety requirements. All necessary precautions will be taken for successful operation of this detector. instrument: 33BM-C fourc instrument_other: minimumdays: 4 name: Prof. Waltraud M. Kriven nonmembers: None submit: Submit unacceptable_dates: 06/26/06 to 06/30/06; 07/30/06 to 08/03/06 z34ID_details: #REMOTE_HOST: mach-21.mse.uiuc.edu #REMOTE_ADDR: 128.174.228.21 #CONTENT_LENGTH: 6730 #HTTP_REFERER: http://www.uni.aps.anl.gov/admin/unireq.html #HTTP_USER_AGENT: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)