Search results for "Forging"

3D reconstruction of hot metallic surfaces for industrial part characterization

2009

During industrial forging of big hot metallic shells, it is necessary to regularly measure the dimensions of the parts, especially the inner and outer diameters and the thickness of the walls, in order to decide when to stop the forging process. The inner and outer diameters of the shells range from 4 to 6 meters and to measure them a large ruler is placed horizontally at the end of the shell. Two blacksmiths standing on each side of the ruler at about ten meters from it visually reads the graduations on the ruler in order to determine the inner and outer diameters from which the thickness of the wall is determined. This operation is carried out several times during a forging process and it…

TITAFORM - Precision Hot Forming, development of innovative hot-forming processes of aeronautical components in Ti-alloy with low buy/fly ratio: an I…

2012

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.

Optimal closed die finish forgings for Nimonic 105 using FEM method

2008

Recent Developments in the Design and Control of Cold Forming Processes

1999

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.

Optically Forged Diffraction-Unlimited Ripples in Graphene

2018

In nanofabrication, just as in any other craft, the scale of spatial details is limited by the dimensions of the tool at hand. For example, the smallest details for direct laser writing with far-field light are set by the diffraction limit, which is approximately half of the used wavelength. In this work, we overcome this universal assertion by optically forging graphene ripples that show features with dimensions unlimited by diffraction. Thin sheet elasticity simulations suggest that the scaled-down ripples originate from the interplay between substrate adhesion, in-plane strain, and circular symmetry. The optical forging technique thus offers an accurate way to modify and shape two-dimens…

Shaping graphene with optical forging: from a single blister to complex 3D structures

2020

Properties of graphene, such as electrical conduction and rigidity can be tuned by introducing local strain or defects into its lattice. We used optical forging, a direct laser writing method, under an inert gas atmosphere, to produce complex 3D patterns of single layer graphene. We observed bulging of graphene out of the plane due to defect induced lattice expansion. By applying low peak fluences, we obtained a 3D-shaped graphene surface without either ablating it or deforming the underlying Si/SiO2 substrate. We used micromachining theory to estimate the single-pulse modification threshold fluence of graphene, which was 8.3 mJ cm−2, being an order of magnitude lower than the threshold for…

An Inverse Approach for the Design of the Optimal Preform Shape in Cold Forging

1998

Abstract In closed die forging the preform design plays a critical role for the success of the process: in fact it must ensure that in the finishing step the desired product is obtained without shape defects such as underfilling or folding and with a minimum material loss into the flash. In the paper an inverse approach is applied to the preform shape optimization problem: the method permits to evaluate a response function which links the set of parameters defining the preform shape with the fulfillment of the product design specifications. The proposed approach has been applied to a closed die forging process aimed to the production of a C-shape component, and has allowed to determine the …

Effectiveness of numerical simulation in avoiding defects in hot extrusion forging products

1999

The hot extrusion forging, in the production of an half shaft of a motorcycle engine, has been analysed by means of finite element simulations. The severe mesh distortion occurring in the simulation has been overcome with the aid of a code provided with automatic remeshing techniques. The study is aimed to promote the use of FEM not only in the designing phase but also as a tool able to investigate defects occurring at the production level.

A Neural Network Based Approach for the Design of FSW Processes

2009

Friction Stir Welding (FSW) is an energy efficient and environmentally "friendly" welding process. The parts are welded together in a solid-state joining process at a temperature below the melting point of the workpiece material under a combination of extruding and forging. This technology has been successfully used to join materials that are difficult-to-weld or ‘unweldable’ by fusion welding methods. In the paper a neural network was set up and trained in order to predict the final grain size in the transverse section of a FSW butt joint of aluminum alloys. What is more, due to the relationship between the extension of the “material zones” and the joint resistance, the AI tool was able to…

The effect of manufacturing tolerances on a tubular linear ferrite motor

2015

This study presents a numerical and experimental study on the effect of permanent magnet tolerances on the performances of a Tubular Linear Ferrite Motor. The statistical distribution of the magnetic characteristic of a set of commercial magnets is obtained experimentally while the performances of a the tubular motor are numerically evaluated. The performances that have been considered are: cogging force, end effect force and generated thrust. It has been shown that: 1)the statistical variability of the magnets modifies the time behavior of the cogging force; 2)the value of both the end effect cogging force and the generated thrust are directly linked to the values of then remanence field o…