Progress towards Understanding the Synthesis and Behavior of Metals Far from Equilibrium: A SMD Symposium Honoring Enrique Lavernia on the Occasion of His 60th Birthday: Light-weight Alloys
Sponsored by: TMS Structural Materials Division, TMS: Mechanical Behavior of Materials Committee, TMS: Advanced Characterization, Testing, and Simulation Committee, TMS: Composite Materials Committee
Program Organizers: Haiming Wen, Missouri University of Science and Technology; Suveen Mathaudhu, Colorado School of Mines; Yuntian Zhu, City University of Hong Kong; Manoj Gupta, National University of Singapore; Kaka Ma, Colorado State University; Troy Topping, California State University Sacramento; Yizhang Zhou, University of California, Irvine; Joshua Yee, Sandia National Laboratories; Dalong Zhang, Pacific Northwest National Laboratory; Yaojun Lin, Wuhan University of Technology; Fei Chen, Wuhan University of Technology

Thursday 2:00 PM
February 27, 2020
Room: 31B
Location: San Diego Convention Ctr

Session Chair: Dalong Zhang, Pacific Northwestern National Laboratory; Yaojun Lin, Wuhan University of Technology


2:00 PM  Cancelled
Annual Progress Report on Magnesium and Magnesium Alloys (2019): Fusheng Pan1; Jiangfeng Song1; 1Chongqing University
     Important progresses on novel magnesium alloys, processing technologies, publications and standards for magnesium and its alloys in the world in the past year are introduced. A super-high plasticity Mg alloy with elongation of higher than 60% has been developed in China. The (c+a) dislocations of various characters in magnesium alloys have been found to accommodate considerable plasticity through gliding on pyramidal planes in submicrometer-size magnesium samples. Journal of Magnesium and Alloys was indexed in SCIE database with the impact factor in 2018 of 4.523, ranking 5 in 76 journals in Metallurgy and Metallurgical Engineering category. ISO 3116:2019, wrought magnesium and magnesium alloys, was published in May, 2019.

2:30 PM  Invited
Characterization of Twin-twin Interactions in Mg: Yanqing Su1; M. Kumar2; Xin Wang3; Yang Hu3; Kehang Yu3; Jiaxiang Wang1; Subhash Mahajan4; Enrique Lavernia3; Tim Rupert3; Julie Schoenung3; Irene Beyerlein1; 1University of California, Santa Barbara; 2Los Alamos National Laboratory; 3University of California, Irvine; 4University of California, Davis
    Mg exhibits limited formability at room temperature because its hexagonal-close packed (HCP) structure has a limited number of activated slip systems. As a result, twinning and detwinning play an important role in plasticity of Mg polycrystalline aggregates. Previous research identified a critical spacing between two twins, beyond which their interactions are negligible. Also analyzed were the effects of the crystallographic orientations of neighboring grains on the critical spacing between parallel twins, but not non-parallel twins. Here, we study the interactions between two twins of parallel or non-parallel relation in Mg using a full-field, crystal plasticity-based fast Fourier transform approach. For both parallel and non-parallel twins, the twin thicknesses are systematically varied to inspect their influences on the critical spacing. For non-parallel twins, the effects of the crystallographic orientations of neighboring grains are also explored. Our results provide insights into the underlying mechanisms of deformation twinning in Mg.

3:00 PM  
From Far-from-Equilibrium Fabrication to Far-from-Equilibrium Investigation – a Case Study for Mg/Mg Alloys at EJL Lab and Beyond: Dalong Zhang1; Lin Jiang2; Xin Wang3; Irene Beyerlein4; Andrew Minor5; Julie Schoenung3; Subhash Mahajan6; Enrique Lavernia3; 1Pacific Northwest National Laboratory; 2Thermo Fisher Scientific; 3University of California, Irvine; 4University of California, Santa Barbara; 5University of California, Berkeley; Lawrence Berkeley National Laboratory; 6University of California, Davis
    Mg-Y alloy with super-saturated solid solution was fabricated at EJL Lab using far-from-equilibrium processes, including gas atomization, hot isostatic pressing, and extrusion. Atom probe tomography (APT) revealed that the resultant alloy contained 1.6 at.% Y solid solution. The Mg-Y alloy exhibited a yield “symmetry”, in that the compressive yield stress (CYS) was nearly the same as the tensile yield stress (TYS), an uncommon and exceptional property compared to other Mg alloys. Post-mortem characterization revealed active prismatic slip and a “lack” of {10-12} deformation twins. In-situ TEM deformation on Mg-Y nano-pillars quantified the critical stresses for basal, prismatic, and pyramidal slip, confirming the multi-faceted effects of Y solid solution in enhancing non-basal slip, reducing intrinsic anisotropy in Mg, and impeding twinning. Far-from-equilibrium in-situ TEM study on pure Mg will also be discussed briefly, unveiling the peculiar behavior of pyramidal <c+a> dislocation in the absence of Y.

3:20 PM  
Role of Laser Surface Modification on Microstructure and Response of a Magnesium Alloy: Bupesh Raja V.K.1; Shaik.Abdul Adil1; Shaik.Mohammed Afridi1; Gururaj Parande2; Sravya Tekumalla2; T. S. Srivatsan3; Manoj Gupta2; 1Sathyabama Institute of Science and Technology; 2National University of Singapore; 3The University of Akron
    The surface engineering of magnesium-base alloys and their composite counterparts is essential to facilitate their selection for use in real time applications.Modification of the surface through use of lasers does provide a unique topography while concurrently resulting in the occurrence of thermal cracking and undesirable changes in microstructural characteristics. In this presentation, details specific to surface of a magnesium alloy (Mg3Al) fabricated using the technique of disintegrated melt deposition (DMD) and subjected to laser ablation under liquid with the prime intent of minimizing drawbacks associated with conventional laser processing while concurrently promoting the formation of a nano-structured surface, magnesium hydroxide and other compounds that contribute to improving functionality will be highlighted. A fibre laser was used to carry out the laser etching studies. The effect of various laser etching patterns, namely: grooves, blind holes and their combinations, was investigated using atomic force microscopy, scanning electron microscopy and Raman spectroscopy.

3:40 PM Break

4:00 PM  Cancelled
Disintegrable Mg/Al Metal Matrix Composites for Oilfield Applications: Zhihui Zhang1; Zhiyue Xu1; 1Baker Hughes, a GE Company
    In the petroleum industry, increasing demand for cost cutting and safety excellence has rendered disintegrable metal composites advantageous efficiency for multistage hydraulic fracturing treatments. In this study, we report disintegrable Mg/Al two-phase composites produced by consolidating the respective metal powders. The Al powder is processed through cryomilling for 12 hrs and exhibits a grain size of 25 nm. The Mg powder is coated with nanocoating to construct a microgalvanic cell and tailor the disintegration rates of the composites. The interaction between the two-phase metal matrix and coatings was studied using differential scanning calorimetry and in-situ scanning electron microscopy. The composites exhibit simultaneous high strength (up to 550 MPa) and two orders of magnitude increase of the corrosion rate (i.e. 250 mg/cm^2/hr) in saline water. The corrosion behavior and engineering performance are discussed in view of improving completion efficiency and reliability in field applications.

4:20 PM  
Microstructure and Texture in Cryomilled and Sintered Ti Grade 2: Dalibor Preisler1; Petr Harcuba1; Josef Strasky1; Hanka Becker2; Tomas Chraska3; Milos Janecek1; 1Charles University; 2TU Bergakademie Freiberg; 3Czech Academy of Sciences
     Titanium Grade 2 was processed by cryogenic milling and subsequently sintered by field assisted sintering technique (FAST) with the aim of creating and preserving the ultra-fine grained microstructure. Microstructural investigation was performed after both milling and sintering, a transmission Kikuchi diffraction was used to characterize the individual milled powder particles. The milled powders showed significant grain refinement down to 50 nm. We assume this to be the equilibrium grain size resulting from the balance of deformation, recovery and dynamic recrystallization. A rolling-like texture was also found in the milled particles as a result of the deformation mechanism during milling.The grain size of the sintered samples ranged from 0.5 to 10 μm, depending on the sintering conditions. Although the grains are completely recrystallized, a texture similar to the powder was also found in these samples as a result of packing of the powder particles and continuous static recrystallization.

4:40 PM  
Cryogenic Milling and Spark Plasma Sintering of Commercially Pure Ti and Metastable Beta Ti15Mo Alloy: Josef Strasky1; Jiri Kozlik1; Anna Veverková1; Petr Harcuba1; Hanka Becker2; Tomas Chraska3; 1Charles University; 2TU Freiberg; 3Institute of Plasma Physics
    This contribution aims on reviewing what we have learnt about cryogenic milling and sintering of Ti based materials in the last five years. Gas atomized CP Ti powder and Ti15Mo alloy powder were cryogenically milled in liquid argon and subsequently sintered by SPS using various processing conditions. Titanium remains ductile even at cryogenic temperatures (unless contaminated by nitrogen) and therefore powders are not significantly refined. On the other hand, each powder particle is severely deformed and cryogenic milling therefore resembles SPD methods for microstructure refinement. UFG structure of powders was studied by transmission Kikuchi diffraction. Samples after sintering were thoroughly characterized. UFG microstructure undergoes recovery and recrystallization during sintering with clear trade-off between remaining porosity and grain growth. Enhanced alpha phase precipitation was observed in the metastable Ti15Mo aloy. Compact UFG Ti15Mo two-phase material is achievable by cryogenic milling and SPS.

5:00 PM  Cancelled
An Advanced MCrAlY with TGO Self Repair Ability: Jianhong He1; 1Oerlikon Metco
    Importance of TBC for engines is well recognized, however, TBC often fails during service due to degradation of TGO. Improvement on TGO performance is critical for TBC lifetime. An advanced MCrAlY alloy has been developed, the new alloy is able to self repair its TGO. For a TBC with a conventional MCrAlY bond coat, TGO grows to very thick, become very brittle, and fracture to lead to TBC spall after long time exposure to high temperature. For the TBC with new alloy bond coat, original TGO damage and leakage of oxygen (diffusion) into bond coat was also observed after long time thermal cycle, however, the new bond coat is able to supply Al to immediately form very thin, uniform and dense fresh Al2O3 TGO to restrict chemical failure of bond coat in a narrow area and keeps the entire coating un-spallation. In this way, TGO self repairs and extends lifetime.

5:20 PM  Cancelled
Research on Microstructure and Mechanical Properties of High Strength Duplex Mg-Li-Al-X Alloys: Yan Yang1; Xiaodong Peng1; 1Chongqing University
    The engineering application of ultra-light Mg-Li alloys is seriously restricted because of their low strength, poor stability and high temperature performance. Duplex structured Mg-Li-Al-X alloys with high strength were designed and prepared via the introduction of alloying element. The microstructure and mechanical properties of Mg-Li-Al-X alloys were investigated systematically combing the usage of many advanced microstructure characterization methods and normal tensile tests, etc. Dynamic precipitation reaction phenomenon was found in duplex Mg-Li-Al-X alloys. The aims of this research involve disclosing the dynamic precipitation reaction mechanism and precipitation regulation mechanism and finding out the strengthening mechanisms in duplex Mg-Li-Al-X alloys. The results from this research contribute to the development of new regulation mechanism for microstructure and mechanical performance in Mg-Li alloys by dynamic precipitation reaction and provide important technological support for the controlling of microstructure and mechanical properties of Mg-Li alloys.

5:40 PM  Cancelled
Overview of Advancement and Development Trend on Magnesium Alloys based on Bibliometric Analysis: Xiaodong Peng1; Yan Yang1; Tiancai Xu1; 1Chongqing University
    Magnesium alloys have become an important lightweight metallic structural material and have been widely studied worldwide. According to the statistical analysis of literature data collected by Web of Science Core Collection, in the past 11 years, it has collected 21440 papers on magnesium alloys, averaging nearly 2000 papers annually, of which 2768 papers were collected in 2018, an increase of 206% over 2008. This article statistically analyzes all the academic articles published by Journal of Magnesium and Alloys from 2013 to 2018 and compares them with all the articles containing magnesium alloy in their titles on the Web of Science during this period. The development trends of magnesium alloys are summarized based on these articles, and the influence and academic value of the articles published by the Journal of Magnesium and Alloys are summarized as well. It hopes to promote the development of global magnesium alloy research.