%0 Journal Article
%T Unprecedented strength in pure iron via high-pressure induced nanotwinned martensite
%A Guilin Wu
%A Hongwang Zhang
%A Jianhua Liu
%A Pinwen Zhu
%A Xiaoxu Huang
%A Yan Peng
%A Yuhui Wang
%A Zongqiang Feng
%J Materials Research Letters
%D 2019
%R https://doi.org/10.1080/21663831.2019.1612792
%X ABSTRACT Martensitic transformation can easily induce a maximum hardness value of 800¨C900£¿HV (Vickers hardness) for steels with carbon contents of 0.6£¿wt.% and above. However, the occurrence of martensitic transformation in pure iron requires exceptionally high cooling rates (105¨C106¡ãC/s), and the maximum achievable hardness is only about 150£¿HV. Here we report an extreme hardness of 830£¿HV in pure iron obtained through high pressure induced martensitic transformation at a rather slow cooling rate of just 10¡ãC/s. This unprecedented strength originates from the formation of twin-related martensitic laths with an average thickness of 3.8£¿nm. GRAPHICAL ABSTRACT IMPACT STATEMENT Slow cooling of pure iron under high pressure induces martensitic transformation, producing nanotwinned martensite with unprecedented strength
%U https://www.tandfonline.com/doi/full/10.1080/21663831.2019.1612792