In-situ Methods for Unraveling Structure-Property Relationships in Light Metals: Poster Session
Sponsored by: TMS Light Metals Division, TMS: Aluminum Committee, TMS: Magnesium Committee
Program Organizers: Dmytro Orlov, Lund University; Wim Sillekens, European Space Agency

Tuesday 6:00 PM
February 28, 2017
Room: Hall B1
Location: San Diego Convention Ctr

I-19: Development of Plasticity Models via Point-by-Point Comparison with HREBSD and Microscale DIC: Timothy Ruggles1; Geoffery Bomarito2; Jacob Hochhalter2; Saikumar Yeratapally1; 1National Institute of Aerospace; 2NASA LaRC
    Advances in microscopy methods have led to an abundance of microstructural information. Attempts to incorporate this information into plasticity models often involve vast reduction of data in order to fit simplified constitutive laws or the use of computationally expensive inverse finite element methods. Coupling of two developing microscopy techniques, high resolution electron backscatter diffraction (HREBSD) and microscale digital image correlation (DIC) provides a unique way to avoid inverse methods without unnecessary data reduction. Using the concurrent measurements of dislocation density from HREBSD and full-field deformation mapping from DIC, hardening rules may be calibrated directly from each point in the microstructure, without the need of a finite element method. To test this concept, an AlCu oligocrystal single edge notch specimen is examined with HREBSD before and after deformation and DIC is performed in situ using an optimized microscale stamp pattern which is then removed for the final HREBSD step.

I-20: Effects of Alloying Elements and Processing on Deformation Mechanisms and Properties of Mg-Li base Alloys: Zhongwu Zhang1; Yun Zou1; Jian Li2; Hong Wang2; Ke An3; 1Harbin Engineering University; 2China Academy of Engineering Physics; 3Oak Ridge National Laboratory
    The widespread application of Mg alloys is still challenging due to their poor room temperature formability. Introducing Li in Mg can significantly increase the ductility due to the deformation mechanisms transition of Mg-Li base alloys. In this sturdy, the plastic deformation mechanisms of binary Mg-Li alloys with single or dual phases are systemically studied by in-situ neutron diffraction with various deformation methods. The effects of alloying elements of Al and Er along with thermomechanical processing on the deformation mechanisms and properties are also investigated and discussed. This work was supported by the NSFC Funding (51371062 and U1460102), NSFHLJ (ZD201411), the Scientific Research Foundation for the Returned Overseas Chinese Scholars (Heilongjiang Province), the Project for Innovative Talents of Science and Technology of Harbin (2014RFXXJ006) and the Project of High-Tech Ships of Ministry of Industry and Information Technology of the People’s Republic of China.

I-21: Parameter Study and Experimental Validation of Crystal-scale Finite Element Analyses of Titanium Alloys: Kayleigh Nelson1; Euan Wielewski1; 1University of Glasgow
    Time to market for new materials in the aerospace industry is typically measured in decades, due to the need to quantify material behaviour and ensure safe usage. Predictive material models contain details of the material’s microstructure and micro-scale mechanical response, they not only reduce this time significantly but inform the design of new materials. Titanium alloys are used in many critical jet engine applications, significant gains in jet engine performance could be realized if software tools were capable of better predicting deformation behaviour. Room-temperature deformation will be examined with the aim of developing software tools capable of predicting deformation and failure. A parameter study, varying single crystal material parameters in crystal-scale finite element simulations will be presented, with emphasis on strain rate sensitivity. Comparisons will be made between simulations and physical experiments using in-situ micro-mechanical testing and high-energy x-ray diffraction. Differences will be investigated enabling refinement of predictive capabilities.

I-22: The Application of Synchrotron X-ray Tomography in the Solidification of Mg Alloys: Enyu Guo1; Sansan Shuai2; André Philliond3; Tao Jing2; Peter Lee1; 1University of Manchester; 2Tsinghua University; 3McMaster University
    Synchrotron X-ray tomography provides a unique non-destructive way of examining 3D or even 4D (3D plus time) measurements with high spatial and temporal resolution. One of such applications is in the study of dendrite formation of hcp Mg alloys, whose dendritic structures are difficult to reveal through 2D observations such as SEM or radiography, due to its complex crystal morphology in 3D. We will show how synchrotron X-ray tomography can be used to investigate dendrite formation in Mg alloys with varying alloy content (Zn, Ca and Sn) to generate different morphologies. The effect of different solutes and the solidification conditions, i.e. equiaxed and directional solidification, will be revealed and discussed. Moreover, in situ 3D studies of selected alloys during solidification and coarsening will also be covered in this presentation, allowing the study of the kinetics of phase transformations to be quantified in real time.