Design of thermomechanical processes for tailored microstructures

Abstract

Thermomechanical processes enable tailoring of material properties and microstructures for advanced products. In medical technology, next-generation titanium implants require tailored material properties to improve health and quality of life. However, the interaction correlation between process parameters and material properties poses a major challenge for the design of thermomechanical manufacturing processes.

In this paper, we present a methodology for the design of thermomechanical processes to achieve tailored microstructural properties through forming technology and heat treatments. The methodology consists of five systematic steps to address the complexity of multiphysical coupling relationships between temperature, stress, microstructure and alloy composition, and to provide a guideline for effective implementation. It is applied to the production of nanostructured Ti-13Nb-13Zr (NanoTNZ) alloy for dental implants. The designed process of severe plastic deformation, recrystallization treatment and aging lead to nanostructured microstructures smaller than 200 nm. The resulting mechanical properties (UTS > 980 MPa, Young’s modulus of 73 GPa) meet the desired goals for improved biomedical implant-bone interactions. The tailored material properties and microstructures of NanoTNZ are therefore highly promising for use as an implant material.

The case study demonstrates the importance of a systematic method to manage the complexity of multiphysical coupling relationships in the design of thermomechanical processes to enable tailored microstructures for advanced materials and products.