Comparative analysis of the structure and internal stress in Ti-6Al-4V alloys manufactured by 3D printing and processing with screw extrusion

N Kazantseva,D Davidov,I Ezhov,A Merkushev,M Ilyinikh,A Fefelov,N Vinogradova,A Volkov

doi:10.1088/1742-6596/1115/4/042007

N Kazantseva, D Davidov + Show 6 more

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https://doi.org/10.1088/1742-6596/1115/4/042007

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Abstract

Study is based on the compare characterization of the structure and evaluation of the residual internal stresses in Ti-6Al-4V samples manufactured by the 3D printing (selective laser melting) and in the Ti-6Al-4V samples obtained with using of the severe plastic deformation by screw extrusion. The microstructure and residual stresses were examined by transmission electron microscope and X-ray diffractometer. High tensile internal residual stresses in the 3D printed sample were found. The high compressive residual internal stresses were found in the hot pressed and in the twisted samples. It was shown that arising of the high residual stresses in the studied samples under various technological processes occurred in various ways. The residual stresses in the severe plastic deformed samples arose due to non-uniform volumetric plastic deformation. In 3D printed sample, the residual tensile stresses arose from both phase (martensitic) transformation and thermal deformation.

Highlights

One of the main tasks of modern developments in the production of titanium alloys is the expansion of the spectrum of metal properties using various processing methods
It was shown that arising of the high residual stresses in the studied samples under various technological processes occurred in various ways
The main objective of this research is the comparison study the residual internal stresses, causes of their origin, and the ways of structural relaxation in the samples manufactured by the 3D printing and in the samples obtained with using of the severe plastic deformation by reverse and comprehensive extrusion

Summary

Introduction

One of the main tasks of modern developments in the production of titanium alloys is the expansion of the spectrum of metal properties using various processing methods. It is known that metals subjected to strong deformations can acquire completely new properties, most of which can be of practical interest They may combine high plasticity with great strength. The method of reverse and comprehensive extrusion with the use of screw extrusion includes several stages of ingot processing and allows one to treat the large-sized ingots [2]. In this case, it is important to know the value of the residual internal stresses after different stages of such treatments to evaluate and predict the mechanical properties of the deformed materials

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