Search results for " Machining"
showing 10 items of 39 documents
Towards criteria for sustainable process selection: On the modelling of pure subtractive versus additive/subtractive integrated manufacturing approac…
2017
Additive Manufacturing (AM) processes can be counted among the disruptive technologies that are capable of transforming conventional manufacturing routes. The ability to create complex geometries, the reduction in material scraps during manufacturing, and the light-weighting due to the think-additive redesign of the components represent the main points of strength of AM. However, for some applications (such as the production of metal components for the automotive and aerospace industries), the surface finishing and dimensional/geometrical part tolerancing that can be achieved via AM processes might not be adequate to satisfy the imposed product specifications, and finish machining operation…
Assessment of material models through simple machining tests
2008
The accuracy of the results obtained from FEM simulation of machining operations depends on the accuracy of input data. Among these, the flow stress data of the workpiece are extremely important together with the friction along the tool-chip interface. In this study, an identification procedure for the determination of material parameters that are used for the FEM simulation of machining processes is proposed. The procedure is based on the coupling of a numerical identification procedure and Arbitrarian Lagrangian Eulerian (ALE) Finite Element simulations of turning operations. An experimental campaign was developed in order to calibrate the model and to validate the procedure. The basic id…
A methodology for evaluating the influence of batch size and part geometry on the environmental performance of machining and forming processes
2016
Metallic material processing plays a significant role in terms of global environmental impact. As a result, energy- and resource-efficient strategies in the metal shaping technology domain need to be identified urgently. Recently, the scientific world has been paying more and more attention to the environmental impact analysis of manufacturing processes. Despite this increased attention, the state of the art in the domain of environmental impact analysis of metal shaping processes is still characterized by gaps in knowledge and in methodologies. In particular, metal forming processes are still not well documented, in terms of their environmental impact, and there is a lack of systematic and…
On the impact of recycling strategies on energy demand and CO2 emissions when manufacturing Al-based components
2016
Abstract The industrial world is facing the challenge of reducing emissions by means of energy- and resource-efficient manufacturing strategies. In some cases, the exerted emissions and the energy demands related to conventional manufacturing processes are not as intensive as those required to extract and produce the raw materials of which the workpieces are made. Therefore, the consciousness of the impact of material usage and the eco-informed choice of the end-of-life scenarios are both needed in view of sustainable development. Aim of this paper is to offer a contribution to a better understanding of the environmental impact of forming and machining processes, for the production of Al-ba…
A comparative assessment of energy demand and life cycle costs for additive- and subtractive-based manufacturing approaches
2020
Abstract The applicability domain of Additive Manufacturing (AM) processes, apart from technological and quality results, relies on environmental and cost performance. These aspects still need to be better understood. To this aim, comparative analyses with conventional manufacturing routes are needed. In this paper, empirical cost and energy requirement models are suggested to assess subtractive- (machining) and additive- (Electron Beam Melting) based manufacturing approaches for the production of Ti-6Al-4V components. A life-cycle perspective is adopted, and all the steps from the input material production to the post-AM processing operations and the use phase are included. The analyses ha…
Design of continuous Friction Stir Extrusion machines for metal chip recycling: issues and difficulties
2018
Abstract Friction Stir Extrusion is an innovative direct-recycling technology developed for metal machining chips. During the process, a rotating die is plunged into a cylindrical chamber containing the material to be recycled. The stirring action of the die prompts solid bonding phenomena allowing the back extrusion of a full dense rod. One of the main weakness of this technology is the discontinuity of the process itself that limits the extrudates volume to the capacity of the chamber. In order to overcome that limitation, a dedicated extrusion fixture has to be developed, keeping into account the concurrent needs of a continuous machine. The geometry of the die has to ensure proper press…
Experimental Research on the Cutting of Metal Materials by Electrical Discharge Machining with Contact Breaking with Metal Band as Transfer Object
2020
The scientific paper presents practical research carried out by a mixed team of Romanian researchers from universities and the business environment. The research consists in applying the process of cutting metallic materials through electrical discharge machining with contact breaking using a metal band as a transfer object. The research was implemented with the help of a specially designed installation in the laboratory and subsequently all the necessary steps were taken to obtain the patent for it. Various metallic materials were cut using this process, but first of all, high alloy steels. In the global research conducted by the authors, active experimental programs and classic experiment…
Magnetite Nanoparticles Prepared By Spark Erosion
2016
Abstract In the present research, we study a possibility of using the electric spark erosion method as an alternative to the method of chemical co-precipitation for preparation of magnetic nanoparticles. Initiation of high frequency electric discharge between coarse iron particles under a layer of distilled water allows obtaining pure magnetite nanoparticles.
Surface finish on hardened bearing steel parts produced by superhard and abrasive tools
2007
New technological process consisting of hard turning (HT) followed by abrasive machining, in place of the widely used method in industry, i.e., hard turning versus grinding, has lately been launched in the automotive industry. This is because, many transmissions parts, such as synchronizing gears, crankshafts and camshafts require superior surface finish along with appropriate fatigue performance. This paper provides a comprehensive characterization of part surface finish produced in dry turning of a hardened AISI 52100 bearing steel using mixed ceramic (MC) and PCBN tools, and also its modification after special abrasive finishing operations including superfinishing (SF) and belt grinding …
A Study on the Correlations between Machining Parameters and Specimen Quality in WEDM
1999
Wire electrical discharge machining (WEDM) is widely used in manufacturing, medical, aircraft applications and, virtually, all areas of conductive material machining. The process involves a series of very complex electrical, thermodynamical and electromagnetical phenomena that are still partially unknown. Due to the large amount of parameters involved in the process, a suitable set-up of the variables aimed to obtain the best performance is often very difficult. In the paper the results of a wide experimental analysis are presented: the tests were carried out on high-speed steel and tempered steel specimens utilising brass wires. The influence of the most important process parameters on the…