The constitutive and damage models of additively manufactured Ti6A14V alloy için kapak resmi
The constitutive and damage models of additively manufactured Ti6A14V alloy
Başlık:
The constitutive and damage models of additively manufactured Ti6A14V alloy
Yazar:
Hızlı, Burak, author.
Yazar Ek Girişi:
Fiziksel Tanımlama:
xvii, 159 leaves: charts;+ 1 computer laser optical disc.
Özet:
Electron Beam Melting (EBM) is one of the metal additive manufacturing methods that enable the fabrication of Ti6Al4V alloy parts with intended shapes in where this alloy is of significant interest such as aerospace and biomedical industries due to its outstanding properties. In this study, the microstructural and mechanical properties of EBM-produced Ti64 were comprehensively investigated. Microstructural analysis was conducted on as-built specimens. Microstructural analysis showed that EBM-produced Ti64 possesses α+β duplex phase with directional microstructural alterations and high porosity fraction in the part volume. Mechanical properties were investigated under tension loadings at quasi-static rates (10-3-10-1 s-1) and compression loading at quasi-static and high strain rates (10-3-2154 s-1). Thereafter, Johnson-Cook (JC) strength and damage models were individually calibrated from the experimental results of tension and compression behaviors and experimental fracture strains in order to numerically predict the material flow behavior of EBM-produced Ti64 considering the strain, strain rate, and temperature effects in the case of various loadings combined with temperature changes. EBM-produced Ti64 exhibited proximate mechanical properties in terms of tension and compression behaviors, however extremely low ductile behavior under tension loadings resulting premature failure without necking. Eventual fracture of this material occurred via tearing of the scanned layers for tension loadings and shear crack following the shear band formation propagation on 45° to loading axis for compression loadings. Calibrated JC strength and damage models for EBM-produced Ti64 were able to predict flow behavior and fracture strains within strain rate range between 10-3 and 103 s-1. However, the JC strength model could not predict the flow behavior at excessively high strain rates (2154 s-1) due to complex deformation mechanisms including adiabatic heating. Keywords: Additive Manufacturing, Electron Beam Melting, Ti6Al4V, Mechanical Properties, Johnson-Cook Strength Model, Johnson-Cook Damage Model
Yazar Ek Girişi:
Tek Biçim Eser Adı:
Thesis (Master)--İzmir Institute of Technology: Mechanical Engineering.

İzmir Institute of Technology: Mechanical Engineering--Thesis (Master).
Elektronik Erişim:
Access to Electronic Versiyon.
Ayırtma: Copies: