Design of a Flexible Down-Scaled Equipment to Reproduce Tube Welding Conditions in Extrusion

TITAFORM - Precision Hot Forming, development of innovative hot-forming processes of aeronautical components in Ti-alloy with low buy/fly ratio: an Italian example of co-operation between academy and industry

In the paper the description of the project TITAFORM is provided. The project has been financed on the call "PON Linea 1" of the Italian government and represents an effective example of cooperation between academy and industry. The project is focused on the beta forging and hot stretch forming operations of titanium alloys. �� 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

An Intelligent Tool to Predict Fracture in Sheet Metal Forming Operations

One of the main issues in sheet metal forming operations design is the determination of formability limits in order to prevent necking and fracture. In fact, the ability to predict fracture represents a powerful tool to improve the production quality in mechanical industry. Many researchers investigated the problem here addressed, mainly studying forming limit diagrams (FLD) or developing fracture criteria which are able to foresee fracture defects for different processes. In this paper, the author present some early results of a research project focused on the application of artificial intelligence (AI) for ductile fracture prediction in sheet metal forming operations. The main advantage o…

Advanced FEM modeling of friction stir welding of Ti6Al4V: Microstructural evolutions

Friction Stir Welding (FSW) is a solid state welding process patented in 1991 by TWI; initially adopted to weld aluminum alloys, is now being successfully used also for high resistant materials. Welding of titanium alloys by traditional fusion welding techniques presents several difficulties due to high material reactivity resulting in bonding with oxygen, hydrogen, and nitrogen with consequent embrittlement of the joint. In this way FSW represents a cost effective and high quality solution. The final mechanical properties of the joints are strictly connected to the microstructural evolutions, in terms of phase change, occurring during the process. In the paper a 3D FEM model of the FSW wel…

Analysis of Some Innovative and Flexible Sheet Forming Processes

In the field of sheet forming, innovative and flexible processes that do not impose the use of expensive conventional equipments and/or do not require time consuming set-up operations have become, nowadays, a rather promising research topic. Two different main lines are currently followed: the former is based on the development of new stamping processes based on the utilization of flexible media, while the latter is aimed to develop so called progressive forming processes (spinning and incremental forming). Both hydro-forming and incremental forming permit a very relevant reduction of the tooling and set-up costs and improve process flexibility. These items are discussed in detail in the pa…

Die design for aluminium thin tubes extrusion: a 2D simulation approach

A simple model for predicting the thermal flow on the tool in orthogonal cutting process

Prediction of Tool Wear in Machining

Forming Processes Design Oriented to Prevent Ductile Fractures

During cold forming processes ductile fractures are sometimes encountered, depending on the operating parameters and on the material properties and determining the production of defective components to be discarded; for this reason the development of a general approach for the prediction of this type of defects is particularly suitable and this aim has been pursued by a large number of researchers in the last two decades. In the paper the most important and diffused models are described and analysed in order to outline the advantages offered by each of them. Some applications to typical metal forming processes are presented, carrying out a comparison between the numerical predictions and th…

Recent Developments in the Design and Control of Cold Forming Processes

In the paper some problems of process design and control in metal forming are taken into account. In particular as far as the former aspect is concerned, the problem of the preform design in cold forging is analyzed: the contributions offered by several researchers are presented and an innovative design procedure is proposed. As well, the suitability of closed-loop control systems for metal forming applications is discussed with particular reference to sheet stamping operations; again, after an overview of the state of the art, the advantages offered by the application in this field of Artificial Intelligence techiniques is pointed out.

The use of artificial intelligence techniques to optimise and control injection moulding processes

In the paper a typical injection moulding process on a single-screw extrusion machine aimed to the production of axisymmetric polypropylene dishes for alimentary use has been investigated. First of all the most important process parameters have been individuated; subsequently a wide testing hyperspace has been investigated, at varying the process parameters in a large range. For each combination both some geometrical characteristics of the obtained component have been measured and the occurrence of defects has been verified. The largest part of the available data have been used to train a neural network aimed to explain the process dynamics. Furthermore an offline control system, based on f…

Key factors for industrial applicability of friction stir welded t-joints of different materials

Numerical prediction of Biphasic Titanium Alloys Microstructure in Hot Forging Operations.

Modern transportation industries shall comply with two demanding requirements: reducing operational consumption together with production costs coming from materials and labour. Current trend of engineering is oriented to meet both requirements increasing the rate of polymer matrix composites which implies association with structures made of titanium alloys. Hot forming can be used to reduce the production costs of titanium components: forging in closed dies of billets or semi finished form, in the temperature range where the Beta phase of titanium is stable, grants an adequate plasticity of the Ti-6Al-4V alloy, the most commercially used, allowing production of complex shapes with limited a…

On the choice of tool material in friction stir welding of titanium alloys