Characterization of Minerals, Metals, and Materials: Electronic, Magnetic, Environmental, and Advanced Materials
Sponsored by: TMS Extraction and Processing Division, TMS: Materials Characterization Committee
Program Organizers: Shadia Ikhmayies, Al Isra University; Bowen Li, Michigan Technological University; John Carpenter, Los Alamos National Laboratory; Jian Li, CanmetMATERIALS; Jiann-Yang Hwang, Michigan Technological University; Sergio Monteiro, Military Institute of Engineering ; Firrao Donato, Collegio Universitario, Italy; Mingming Zhang, ArcelorMittal Global R&D; Zhiwei Peng, Central South University; Juan P. Escobedo-Diaz, UNSW Australia; Chenguang Bai, Chongqing University; Eren Kalay, METU; Ramasis Goswami, Naval Research Laboratory; Jeongguk Kim, Korea Railroad Research Institute
Monday 2:00 PM
February 27, 2017
Location: San Diego Convention Ctr
Session Chair: Shadia Ikhmayies, Al Isra University; Zhiwei Peng, Central South University
Characterization of Defects in Metal Oxide Thin Films Using Electron Channeling Contrast Imaging (ECCI) and TEM: Isha Kashyap1; Marc De Graef1; 1Carnegie Mellon University
Metal oxide thin films exhibit interesting high temperature properties. La1-xSrxMnO3 (LSM) is well known for its application as a cathode material in Solid Oxide Fuel Cells (SOFC). LSM is also ferromagnetic and exhibits Colossal Magneto Resistance (CMR). The lattice mismatch between thin film and substrate creates a misfit strain which produces a host of extended defects. Quantifying these defects and their displacement vectors within a material is important for understanding how defects can affect the material properties, in particular the magnetic and electrical properties. In this study, we employ Electron Channeling Contrast Imaging (ECCI), an SEM-based non-destructive technique, to characterize, quantitatively, various kinds of defects including APBs, dislocations and twin boundaries in LSM and other oxide thin films. We also analyze the magnetic microstructure using Lorentz TEM, and compare these results with data acquired from ECCI to understand the interactions between magnetic domain walls and crystallographic defects.
Characterization of Low-zinc Electric Arc Furnace Dust: Zhiwei Peng1; Xiaolong Lin1; Jiaxing Yan1; Jiann-Yang Hwang1; Yuanbo Zhang1; Guanghui Li1; Tao Jiang1; 1Central South University
Electric arc furnace (EAF) dust is an important secondary resource that should be recycled to enhance its considerable economic value and potential environmental benefit. In this study, a low-zinc EAF dust was characterized by various techniques, including chemical titration, X-ray diffraction, granulometric analysis, scanning electron microscopy and thermogravimetry. It is shown that the dust contains 2.08 wt.% Zn, 23.16 wt.% Fe and 19.84 wt.% Ca, accompanying small amounts of Cr, Pb, etc. Magnetite, calcium ferrite and zinc ferrite are the main phase constituents. The majority (90%) of particles have size less than 137.862 μm. According to these characteristics, it is expected that the use of microwave energy for intensification of the reduction of EAF dust in the presence of biochar will succeed in the dust recycling by promoting the processing efficiency with elimination of secondary hazardous pollutants.
Formation of ZrO2 in Coating on AZ31 Mg Alloy via Plasma Electrolytic Oxidation: Phase and Structure of Zirconia: Jung-Woo Choi1; Gye-Won Kim1; Bongyoung Yoo1; Dong-Hyuk Shin1; 1Hanyang University
An investigation of the coating structure formed on AZ31 Mg alloy sample subjected to plasma electrolytic oxidation was examined by field-emission transmission electron microscopy. The plasma electrolytic oxidation process was conducted in a phosphoric acid electrolyte containing K2ZrF6 for 600 s. Microstructural observations showed that the coating consisting of MgO, MgF2, and ZrO2 phases was divided into three distinctive parts, the barrier, intermediate, and outer layers. Nanocrystalline MgO and MgF2 compounds were observed mainly in the barrier layer of ~1 μm thick near to the substrate. From the intermediate to outer layers, various ZrO2 polymorphs appeared due to the effects of the plasma arcing temperature on the phase transition of ZrO2 compounds during the plasma electrolytic oxidation process. In the outer layer, MgO compound grew in the form of a dendrite-like structure surrounded by cubic ZrO2.
Gamma-radiation Effect on Biodegradability of Synthetic PLA Structural Foams PP/HMSPP Based: Elizabeth Cardoso1; Sandra Scagliusi1; Ademar Lugăo1; 1IPEN - Instituto de Pesquisas Energéticas e Nucleares
This research investigated how gamma-radiation affected PP/HMSPP structural foams filled with biodegradable synthetic polyester PLA in terms of thermal properties, biodegradability and infrared spectrum. Polymers are used in various applications providing enormous quantities of wastes in environment and contributing with 20 to 30% of total volume of solid residues. Besides, shortage of plastics resins obtained from fossil base is addressing research and development toward alternative materials; environmental concerning in litter reduction is being directed to renewable polymers for manufacturing of polymeric foams. Biodegradable polymers, a new generation of polymers produced from various natural resources, environmentally safe and friendly, can contribute for pollution reduction. PLA (poly(lactic) acid)) was chosen to be blended with PP/HMSPP. Blends thereof were subjected to gamma radiation at 50, 100, 150, 200 and 500 kGy doses. Soil burial test pointed toward a partial biodegradation of irradiated PLA-PP/HMSPP foams; other characterizations involved TG/DTG technique and FTIR assessments.
Study of Flexible Films Prepared From PLA/PBAT Blend and PLA E-Beam Irradiated as Compatibilizing Agent: Elizabeth Cardoso1; Esperidiana Moura, A. B.1; Glauson Mahado1; René Oliveira1; 1IPEN - Instituto de Pesquisas Energéticas e Nucleares
Plastics global annual production exceeds 250 million tons and more than 40 % of the total plastic production is used as packaging materials. In recent years polymeric materials derived from biomass have received great attention due to scarce petroleum resources and environmental concerns. PLA is one of the most extensively studied bio-based and biocompostable aliphatic polyesters; nevertheless, high brittleness and low toughness limits its application. Blending PLA with PBAT (Poly (butylene adipate-co-terepthalate), an aliphatic-aromatic copolyester, was the solution found due to its high toughness and biodegradability. Differences between PLA and PBAT solubility parameter values lead to the formation of immiscible blends as well as reduction in their mechanical performance besides a poor morphology; so, 5% of pre-irradiated PLA and a previous compatibilized PLA/PBAT (EcovioTM) were added to PLA/PBAT blends in order to improve miscibility phases. Investigations were accomplished on phase morphology (SEM), mechanical properties, thermal behavior and X-ray diffractions (XRD).
3:40 PM Break
Study on the Electrically Assisted Springback Reduction of Super-elastic Titanium Alloys: Yong-Ha Jeong1; Viet Tien Luu1; Trung Thien Nguyen1; Sung-Tae Hong1; Hyunwoo So2; Heung Nam Han3; Sangwoo So4; Hyun-Tae Hwang4; 1University of Ulsan; 2LG electronics; 3Seoul National University; 4Ulsan Technopark
Electrically assisted springback reduction of super-elastic titanium alloys is demonstraed by u-bending experiments and the effect of electric current on the resultant meachnical properties is evaulated. Experimental set-up is estabilished by combining u-bending fixture and an electric current generator. The experimental result shows that the springback of the selected super-elastic titanium alloy could be nearly eliminated by applying electric current with a duration less than 500 ms to the specimen prior to unloading. The result of microstructural analysis confirms the electric current effectively reduces the dislocation density in the strain hardened specimen.
Electrical and Microstructural Investigation of Ni0.5Co0.5Cu0.3Zn0.3Mn1.4O4 Temperature Sensors: Gökhan Hardal1; Berat Yüksel Price1; 1Istanbul University
Nickel manganite based negative temperature coefficient (NTC) thermistors have good temperature sensor characteristics and electrical stability for temperature measurement applications. In this study, the electrical and microstructural properties of Ni0.5Co0.5Cu0.3Zn0.3Mn1.4O4 NTC thermistors were investigated. The samples were fabricated by conventional solid-state reaction method. The powders were calcined at 900oC for 2 hours and the samples were sintered at 1200 and 1300oC for 5 hours in air. The bulk density of samples was 5.07 and 4.96 g/cm3, respectively. The microstructure of samples was observed using a scanning electron microscopy. The electrical resistance was measured in a temperature programmable furnace between 25oC and 85oC. The electrical resistivity of Ni0.5Co0.5Cu0.3Zn0.3Mn1.4O4 sample increased from 52 Ω.cm to 94 Ω.cm when the sintering temperature increased from 1200 to 1300oC. The material constant “B”, sensitivity coefficient “α” and activation energy “Ea” values were also calculated for the NTC thermistors.
Domain Wall Behavior and Phase Transitions of Ba(Zr0.2Ti0.8)O3-50(Ba0.7Ca0.3)TiO3 under Frequency of 0.2Hz-1.2 MHz: Le Zhang1; Michael Carpenter2; Xiaobing Ren1; 1Xi'an Jiaotong University; 2University of Cambridge
Ba(Zr0.2Ti0.8)O3-50(Ba0.7Ca0.3)TiO3 (BZT-50BCT) with ultrahigh piezoelectricity of d33= 580~620pC/N, has attracted much attention from academic institutions or industrial companies. In this work, we mainly characterize its elastic behavior, domain wall dynamics and phase transitions in wide frequency range by utilizing Resonant Ultrasound Spectroscopy (RUS, 0.1-1.2MHz), dielectric permittivity (LCR, 60Hz-100kHz) and dynamic modulus analysis (DMA, 0.2-20Hz) with varying temperature. We found there are two phase transitions existing at the MPB of BZT-50BCT no matter under higher or lower electric or elastic activated signal, confirming the existence of an independent intermediate orthorhombic phase. We also make clear the contribution of non-180° domain wall motion to the large piezoelectricity at the MPB of BZT-50BCT. Furthermore, the non-180°domain wall motion exhibits differently in DMA and RUS, higher kinetics in DMA than that in RUS. This is considered to be associated with that RUS with low activation exclude long range domain wall motion.
Synthesis of ZnO Micro Prisms on Glass Substrates by the Spray Pyrolysis Method: Shadia Ikhmayies1; 1Al Isra University
ZnO micro prisms in thin film form were produced by the low cost spray pyrolysis technique at a substrate temperature of 350 ± 5 °C on glass substrates. Scanning electron microscopy (SEM) and energy dispersion X-ray spectroscopy (EDS) were used to explore morphology and composition of the films respectively. The films were found to be oxygen rich and contain chlorine. ImageJ software was used to analyze the size of the prisms, where the diameter and length of the micro prisms were estimated.