Search results for "Ti-6Al-4V"

Influence of Material-Related Aspectsof Additive and Subtractive Ti-6Al-4VManufacturing on Energy Demandand Carbon Dioxide Emissions

2017

The additive manufacturing of metal parts represents a promising process that could beused alongside traditional manufacturing methods. The research scenario in this field isstill largely unexplored, as far as the technological solutions adopted to integrate differentprocesses are concerned and in terms of environmental and economic impact assessment.In this article, an electron beam melting (EBM) process and a machining process have beenanalyzed and compared using a cradle-to-grave life cycle–based approach. The productionof components made of the Ti-6Al-4V alloy has been assumed as a case study. Theproposed methodology is able to account for all of the main factors of influence on energydem…

Coupled thermo-mechanical-metallurgical analysis of an hot forging process of titanium alloy

2013

Application of a rheological Model for Phase Transformation Prediction in Beta Processing of Titanium Alloys

2013

The paper shows a description of a numerical model able to simulate a complete forming process of Ti-6Al-4V titanium alloy that is a multi-phasic alloy composed, at room temperature, by two main different phases, namely Alpha and Beta, which evolve during both cooling and heating processes. The characterization of the material behavior concerns both the thermo-mechanical and metallurgical data in order to set a valid tri-coupled thermo-mechanical-metallurgical analysis systems taking into account the effects and interactions of all the phenomena resulting from the coupling of thermal, mechanical and metallurgical events. The numerical model was used to simulate a double numerical campaign r…

Experimental and Numerical Analysis of Microstructure Evolution during Linear Friction Welding of Ti6Al4V

2015

Abstract Linear Friction Welding (LFW) is a solid state welding process used to joint bulk components. In the paper, an experimental and numerical study on LFW of Ti6Al4V titanium alloy is presented. A laboratory designed LFW machine has been used to weld the specimens with different contact pressure and oscillation frequency. The joint microstructure has been experimentally observed with SEM and EDS. A dedicated numerical model, able to predict temperature, strain and strain rate distribution as well as the phase volume fraction evolution, has been utilized to predict the final microstructure in the welded parts. It was found that complete transformation of the alpha phase into beta phase …

Beta forging of Ti-6Al-4V: Microstructure evolution and mechanical properties

2013

Titanium alloys are finding an increasing use in the aeronautical field, due to their characteristics of high mechanical properties, lightness and corrosion resistance. Moreover these alloys are compatible with the carbon fibre reinforced plastics that are also finding a wide use in the aeronautical field. On the other hand the use of these alloys implies some drawbacks, for example titanium alloys are often considered more difficult to form and generally have less predictable forming characteristics than other metallic alloys such as steel and aluminum. In this paper was studied both the microstructure evolution and the mechanical properties of a Ti-6Al-4V rolled bar after hot forging. The…

Beta-forging of Ti6Al4V titanium alloy powders consolidated by HIP: Plastic flow and strain-rate relation

2014

Ti6Al4V is probably the best known and studied titanium alloy, not only for aerospace applications. Nevertheless the deformation behavior still represents a challenge if any modification in the deformation process is required or introduced. This work deals with deformation behavior description of Ti6Al4V HIPped powders during high temperature deformation tests carried on in the Beta-region. Laboratory compression and tensile tests have been coupled with relaxation tests in order to achieve robust data about strain rate sensibility m-coefficient and activation energy Q. These results have been fitted for the assessment of a more general exponential deformation law. The final result is a “Dor…

Prediction of phase transformation of Ti-6Al-4V titanium alloy during hot-forging processes using a numerical model

2013

In this article numerical model for prediction of phase evolution of Ti-6Al-4V titanium alloy was presented. In particular, attention was focused on alpha to beta and beta to alpha+beta phase transformations. The analysis was conducted using a commercial implicit finite element method code, considering the data and the parameters of a real case study to check the quality of the numerical model. The alpha to beta transformation was developed using the simplified form of the Avrami model and the beta to alpha+beta transformation was controlled through the generalized Avrami model. The model so-thought has been used to conduct a 2D simulation of a forging process. A comparison between the num…

Influence of geometrical ratios in forgeability of complex shapes during hot forging of Ti-6Al-4V titanium alloy

2014

Abstract Titanium alloys are considered desirable materials when both mechanical properties and weight reduction are requested at the same time. This class of materials is widely used in application fields, like aeronautical, in which common steels and light-weight materials, like aluminum alloys, are not able to satisfy all operative service conditions. Most of manufacturing processes of titanium alloy components are based on machining operations, which allow obtaining very accurate final shapes but, at the same time, are affected by several disadvantage like material waste and general production costs. During the last decade, the forging processes for titanium alloys have attracted greate…

COMPUTER AIDED ENGINEERING FOR THERMO-MECHANICAL-METALLURGICAL ANALYSIS OF FORGING OPERATIONS OF TITANIUM ALLOYS

In this thesis a study on the forging processes of Ti-6Al-4V titanium alloy, with particular focus on the numerical applications and simulation design of hot forming methods, was done. The aim of this work is to collect all data concerning the material definition in terms of thermal, mechanical and microstructural properties of the selected alloy in order to filter all useful information to describe the behavior of the material under the characteristic conditions of the hot forging processes, taking into account both thermo-mechanical and metallurgical aspects involved during a such complex thermo-mechanical stage. Those information were collected and used to characterize the material prope…

An Automated Visual Inspection System for the Classification of the Phases of Ti-6Al-4V Titanium Alloy

2013

Metallography is the science of studying the physical properties of metal microstructures, by means of microscopes. While traditional approaches involve the direct observation of the acquired images by human experts, Com-puter Vision techniques may help experts in the analysis of the inspected mate-rials. In this paper we present an automated system to classify the phases of a Titanium alloy, Ti-6Al-4V. Our system has been tested to analyze the final products of a Friction Stir Welding process, to study the states of the micro-structures of the welded material.