Microstructure and dynamic strain aging behavior in oxide dispersion strengthened 91Fe-8Ni-1Zr (at%) alloy

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:725

Article

Barton, Dallin J.¹  Kale, Chaitanya²  Hornbuckle, B. Chad³  Darling, Kristopher A.³  Solanki, Kiran N.²  Thompson, Gregory B.¹ 

[1] Univ Alabama, Dept Met & Mat Engn, Box 870202, Tuscaloosa, AL 35487 USA

[2] Arizona State Univ, Sch Engn Matter Transport & Energy, Tempe, AZ 85287 USA

[3] US Army, Res Lab, Weap & Mat Res Directorate, Aberdeen, MD 21005 USA

关键词: Atom probe tomography;    ODS steel;    High rate;    Dynamic strain aging;   

DOI  :  10.1016/j.msea.2018.04.016

来源: Elsevier

【 摘 要 】

Mechanically alloyed 91Fe-8Ni-1Zr (at%) powders were fabricated through high energy ball milling of elemental powder and subsequently consolidated via equal channel angular extrusion (ECAE) at 800 degrees C and 1000 degrees C. The resulting microstructure was fine grain with a nano-dispersion of Zr-oxide within the matrix, which was spherical for the 800 degrees C. ECAE and plate-like (and volumetrically larger) for the 1000 degrees C ECAE conditions. Atom probe tomography confirmed trace levels of C, N, and Cr impurities within the alloy making it similar to a low-carbon steel. By performing mechanical testing at a quasi-static strain rate (10(-3)s(-1)) and at high strain rate (10(3)s(-1)) at room temperature and 473 K, a load drop was noted after yielding. In general, this load drop became more pronounced with increasing strain rate and temperature and has been shown to be a result of dynamic strain aging in the ODS alloy.

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