Acknowledgements

Parts of this chapter are reproduced from authors' previous publication (Ref. [11]).

**Chapter 5**

**Provisional chapter**

**Improving Contact Load-Bearing Resistance of**

**Improving Contact Load-Bearing Resistance of** 

Dengke Yang, Jiangting Wang, Huimin Yang and

Dengke Yang, Jiangting Wang, Huimin Yang and

Additional information is available at the end of the chapter

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.72197

**Grading**

**Grading**

Peter Hodgson

**Abstract**

to loading damage.

Peter Hodgson

**Ultrafine-Grained Materials Through Multilayering and**

Structural multilayering and grading has been designed to improve the contact loadbearing resistance of ultrafine-grained materials. The contact load-bearing response and surface damage resistance of multilayered hierarchical structured (MHSed) Ti were evaluated by experimental indentation on the overall loading response in conjunction with detailed computational simulations of local stresses and strain distribution. The combination of a hard outer layer, a gradual transition layer and a compliant core results in reduced indentation depth, but a deeper and more diffuse sub-surface plastic deformation zone, compared to the monolithic nanostructured Ti. The macroscopic indentation resistance of MHSed Ti is controlled by the underlying micromechanics of the multilayered hierarchical structure. The finite element analysis (FEA) revealed the multilayered hierarchical structure offers the effective macroscopic mechanical contact loading resistance, where the indenter increasingly "senses" the more compliant core to bear the deformation as the load increases. The structural multilayering modifies the stress and strain redistribution and effectively reduces the maximum stress concentration within the material. The structural grading provide a transitional junction for stress and plastic deformation redistribution and achieve more gradual stress distributions between component layers which mitigates the interface failure, increases the interfacial toughness, thus providing strong resistance

**Ultrafine-Grained Materials Through Multilayering and** 

DOI: 10.5772/intechopen.72197

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution,

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

distribution, and reproduction in any medium, provided the original work is properly cited.

and reproduction in any medium, provided the original work is properly cited.

**Keywords:** ultrafine-grained materials, multilayered hierarchical structure, multilayering, grading, contact load-bearing resistance, finite element modeling
