Back stress strengthening and strain hardening in gradient structure

By Muxin Yang, Yue Pan, Fuh-Gwo Yuan, Yuntian Zhu, Xiaolei Wu. 2016

1,356 citations recorded by the source corpus.

We report significant back stress strengthening and strain hardening in gradient structured (GS) interstitial-free (IF) steel. Back stress is long-range stress caused by the pileup of geometrically necessary dislocations (GNDs). A simple equation and a procedure are developed to calculate back stress basing on its formation physics from the tensile unloading–reloading hysteresis loop. The gradient structure has mechanical incompatibility due to its grain size gradient. This induces strain gradient, which needs to be accommodated by GNDs. Back stress not only raises the yield strength but also significantly enhances strain hardening to increase the ductility. Impact Statement: Gradient structure leads to high back stress hardening to increase strength and ductility. A physically sound equation is derived to calculate the back stress from an unloading/reloading hysteresis loop. GRAPHICAL ABSTRACT

Subfields: Materials Chemistry, Mechanical Engineering, Mechanics of Materials

View Paper: https://www.semanticscholar.org/paper/fab1bf97c76c42b0dec15bf47d01b1e6fa3c0f2d

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Materials Chemistry

1. Yuntian Zhu
2. Xiaolei Wu
3. I. Ovid’ko
4. R. Valiev
5. Yonghao Zhao
6. Hyoung-Seop Kim
7. Yang Cao
8. Fuh-Gwo Yuan

In Mechanical Engineering

1. Yuntian Zhu
2. Xiaolei Wu
3. R. Valiev
4. I. Ovid’ko
5. Yonghao Zhao
6. Hyoung-Seop Kim
7. Yang Cao
8. Hao Zhou

In Mechanics of Materials

1. Yuntian Zhu
2. Xiaolei Wu
3. I. Ovid’ko
4. R. Valiev
5. Yonghao Zhao
6. Hyoung-Seop Kim
7. Yang Cao
8. Hao Zhou

Citations in the corpus

• Additional hardening in harmonic structured materials by strain partitioning and back stress (2018, background): “Several studies [10,21] reported the back stress hardening in heterogeneous structures, such as heterogeneous lamella structure.”
• Perspective on hetero-deformation induced (HDI) hardening and back stress (2019, methodology): “Second, the HDI stress (measured ‘back stress’ in the literature [2,27]) appears to increase quickly in the elastic-plastic deformation stage, but slows down during”
• Selective laser melting enabling the hierarchically heterogeneous microstructure and excellent mechanical properties in an interstitial solute strengthened high entropy alloy (2019, background): “Additionally, the back stress that is beneficial to the work-hardening is likely to be developed due to the heterogeneous microstructures of the as-built iHEA [15,26,27].”
• Review on superior strength and enhanced ductility of metallic nanomaterials (2018, background): “The high mechanical incompatibility between domains leads to strain gradient near their interfaces/domain boundaries, which need to be accommodated by geometrically necessary dislocations [387,388].”
• Combining Gradient Structure and TRIP Effect to Produce Austenite Stainless Steel with High Strength and Ductility (2016, background): “It has been reported that mechanical incompatibility will also cause high back stress and back stress hardening [35,58].”