naa a22 4500 510772226 CHVBK 20180411083218.0 cr unu---uuuuu 180411e20130201xx s 000 0 eng 10.1007/s11837-012-0516-9 doi (NATIONALLICENCE)springer-10.1007/s11837-012-0516-9 Extracting Constitutive Stress-Strain Behavior of Microscopic Phases by Micropillar Compression [Elektronische Daten] [J. Williams, J. Walters, M. Wang, N. Chawla, A. Rohatgi] The macroscopic behavior of metallic materials is a complex function of microstructure. The size, morphology, volume fraction, crystallography, and distribution of a 2nd phase within a surrounding matrix all control the mechanical properties. Understanding the contributions of the individual microconstituents to the mechanical behavior of multiphase materials has proven difficult due to the inability to obtain accurate constitutive relationships of each individual constituent. In dual-phase steels, for example, the properties of martensite or ferrite in bulk form are not representative of their behavior at the microscale. In this study, micropillar compression was employed to determine the mechanical properties of individual microconstituents in metallic materials with "composite” microstructures, consisting of two distinct microconstituents: (I) a Mg-Al alloy with pure Mg dendrites and eutectic regions and (II) a powder metallurgy steel with ferrite and martensite constituents. The approach is first demonstrated in a Mg-Al directionally solidified alloy where the representative stress-strain behavior of the matrix and eutectic phases was obtained. The work is then extended to a dual-phase steel where the constitutive behavior of the ferrite and martensite were obtained. Here, the results were also incorporated into a modified rule-of-mixtures approach to predict the composite behavior of the steel. The constitutive behavior of the ferrite and martensite phases developed from micropillar compression was coupled with existing strength-porosity models from the literature to predict the ultimate tensile strength of the steel. Direct comparisons of the predictions with tensile tests of the bulk dual-phase steel were conducted and the correlations were quite good. TMS, 2012 Williams J. Materials Science and Engineering, Arizona State University, 85287-6106, Tempe, AZ, USA aut Walters J. Materials Science and Engineering, Arizona State University, 85287-6106, Tempe, AZ, USA aut Wang M. Materials Science and Engineering, Arizona State University, 85287-6106, Tempe, AZ, USA aut Chawla N. Materials Science and Engineering, Arizona State University, 85287-6106, Tempe, AZ, USA aut Rohatgi A. Energy Materials Group, Pacific Northwest National Laboratory, 99354, Richland, WA, USA aut JOM Springer US; http://www.springer-ny.com 65/2(2013-02-01), 226-233 1047-4838 65:2<226 2013 65 11837 https://doi.org/10.1007/s11837-012-0516-9 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11837-012-0516-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Williams J. Materials Science and Engineering, Arizona State University, 85287-6106, Tempe, AZ, USA aut NATIONALLICENCE 700 1- Walters J. Materials Science and Engineering, Arizona State University, 85287-6106, Tempe, AZ, USA aut NATIONALLICENCE 700 1- Wang M. Materials Science and Engineering, Arizona State University, 85287-6106, Tempe, AZ, USA aut NATIONALLICENCE 700 1- Chawla N. Materials Science and Engineering, Arizona State University, 85287-6106, Tempe, AZ, USA aut NATIONALLICENCE 700 1- Rohatgi A. Energy Materials Group, Pacific Northwest National Laboratory, 99354, Richland, WA, USA aut NATIONALLICENCE 773 0- JOM Springer US; http://www.springer-ny.com 65/2(2013-02-01), 226-233 1047-4838 65:2<226 2013 65 11837 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer