Massive interstitial solid solution alloys achieve near-theoretical strength

Chang Liu; Wenjun Lu; Wenzhen Xia; Chaowei Du; Ziyuan Rao; James P Best; Steffen Brinckmann; Jian Lu; Baptiste Gault; Gerhard Dehm; Ge Wu; Zhiming Li; Dierk Raabe

doi:10.1038/s41467-022-28706-w

Massive interstitial solid solution alloys achieve near-theoretical strength

Nat Commun. 2022 Mar 1;13(1):1102. doi: 10.1038/s41467-022-28706-w.

Authors

Chang Liu¹, Wenjun Lu², Wenzhen Xia³, Chaowei Du¹, Ziyuan Rao¹, James P Best¹, Steffen Brinckmann^{1

4}, Jian Lu⁵, Baptiste Gault^{1

6}, Gerhard Dehm¹, Ge Wu⁷, Zhiming Li^{8

9}, Dierk Raabe¹⁰

Affiliations

¹ Max-Planck-Institut für Eisenforschung, Max-Planck-Straße 1, 40237, Düsseldorf, Germany.
² Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen, China.
³ School of Metallurgical Engineering, Anhui University of Technology, Maanshan, 243000, China.
⁴ Microstructure and Properties of Materials (IEK-2), Forschungszentrum Jülich, 52425, Jülich, Germany.
⁵ Department of Mechanical Engineering, City University of Hong Kong, Hong Kong, China.
⁶ Department of Materials, Royal School of Mine, Imperial College London, London, SW7 2AZ, UK.
⁷ Center for Advancing Materials Performance from the Nanoscale (CAMP-Nano) and Hysitron Applied Research Center in China (HARCC), State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China. gewuxjtu@xjtu.edu.cn.
⁸ School of Materials Science and Engineering, Central South University, Changsha, 410083, China. zhiming.li@mpie.de.
⁹ Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Central South University, Changsha, 410083, China. zhiming.li@mpie.de.
¹⁰ Max-Planck-Institut für Eisenforschung, Max-Planck-Straße 1, 40237, Düsseldorf, Germany. d.raabe@mpie.de.

Abstract

Interstitials, e.g., C, N, and O, are attractive alloying elements as small atoms on interstitial sites create strong lattice distortions and hence substantially strengthen metals. However, brittle ceramics such as oxides and carbides usually form, instead of solid solutions, when the interstitial content exceeds a critical yet low value (e.g., 2 at.%). Here we introduce a class of massive interstitial solid solution (MISS) alloys by using a highly distorted substitutional host lattice, which enables solution of massive amounts of interstitials as an additional principal element class, without forming ceramic phases. For a TiNbZr-O-C-N MISS model system, the content of interstitial O reaches 12 at.%, with no oxides formed. The alloy reveals an ultrahigh compressive yield strength of 4.2 GPa, approaching the theoretical limit, and large deformability (65% strain) at ambient temperature, without localized shear deformation. The MISS concept thus offers a new avenue in the development of metallic materials with excellent mechanical properties.