Near net shape manufacturing of metal : a review of approaches and their evolutions

In the last thirty years the concept of manufacturability has been applied to many different processes in numerous industries. This has resulted in the emergence of several different "Design for Manufacturing" methodologies which have in common the aim of reducing productions costs through the application of general manufacturing rules. Near net shape technologies have expanded these concepts, targeting mainly primary shaping process, such as casting or forging. The desired outcomes of manufacturability analysis for near-net-shape (NNS) processes are cost and lead/time reduction through minimization of process steps (in particular cutting and finishing operations) and raw material saving. Product quality improvement, variability reduction and component design functionality enhancement are also achievable through NNS optimization. Process parameters, product design and material selection are the changing variables in a manufacturing chain that interact in complex, non-linear ways. Consequently modeling and simulation play important roles in the investigation of alternative approaches. However defining the manufacturing capability of different processes is also a “moving target” because the various NNS technologies are constantly improving and evolving so there is challenge in accurately reflecting their requirements and capabilities. In the last decade, for example, CAD, CNC technologies and innovation in materials have impacted enormously on the development of NNS technologies. This paper reviews the different methods reported for NNS manufacturability assessment and examines how they can make an impact on cost, quality and process variability in the context of a specific production volume. The discussion identifies a lack of structured approaches, poor connection with process optimization methodologies and a lack of empirical models as gaps in the reported approaches

Data-mining modeling for the prediction of wear on forming-taps in the threading of steel components

An experimental approach is presented for the measurement of wear that is common in the threading of cold-forged steel. In this work, the first objective is to measure wear on various types of roll taps manufactured to tapping holes in microalloyed HR45 steel. Different geometries and levels of wear are tested and measured. Taking their geometry as the critical factor, the types of forming tap with the least wear and the best performance are identified. Abrasive wear was observed on the forming lobes. A higher number of lobes in the chamber zone and around the nominal diameter meant a more uniform load distribution and a more gradual forming process. A second objective is to identify the most accurate data-mining technique for the prediction of form-tap wear. Different data-mining techniques are tested to select the most accurate one: from standard versions such as Multilayer Perceptrons, Support Vector Machines and Regression Trees to the most recent ones such as Rotation Forest ensembles and Iterated Bagging ensembles. The best results were obtained with ensembles of Rotation Forest with unpruned Regression Trees as base regressors that reduced the RMS error of the best-tested baseline technique for the lower length output by 33%, and Additive Regression with unpruned M5P as base regressors that reduced the RMS errors of the linear fit for the upper and total lengths by 25% and 39%, respectively. However, the lower length was statistically more difficult to model in Additive Regression than in Rotation Forest. Rotation Forest with unpruned Regression Trees as base regressors therefore appeared to be the most suitable regressor for the modeling of this industrial problem.ThisinvestigationwaspartiallysupportedbyProjects TIN2011-24046,IPT-2011-1265-020000andDPI2009- 06124-E/DPIoftheSpanishMinistryofEconomyand Competitiveness.WethanktheUFIinMechanicalEngineer- ing oftheUPV/EHU(UFIMECA-1.0.2016(ext))forits support

Production Engineering Strategies and Metalworking at Toyota Motor Corporation

AbstractVehicles consist of a large number of products of different shapes and sizes. These products can be manufactured very efficiently by metalworking. Products manufactured by metalworking also have superior mechanical properties, such as strength and elongation; these are useful in reducing vehicle weight which leads to improved fuel efficiency and performance. In addition, these products help to reduce cost. Toyota Motor Corporation considers metalworking as a source of competitiveness and has continued to develop innovative metalworking technologies over many years as a means of responding to changes in the social environment and customer needs. This paper describes the history of this innovation, explains the current challenges, and also discusses the direction of future innovations

Best Practices from the Design and Development of the Ares I Launch Vehicle Roll and Reaction Control Systems

On April 15, 2010 President Barak Obama made the official announcement that the Constellation Program, which included the Ares I launch vehicle, would be canceled. NASA s Ares I launch vehicle was being designed to launch the Orion Crew Exploration Vehicle, returning humans to the moon, Mars, and beyond. It consisted of a First Stage (FS) five segment solid rocket booster and a liquid J-2X Upper Stage (US) engine. Roll control for the FS was planned to be handled by a dedicated Roll Control System (RoCS), located on the connecting interstage. Induced yaw or pitch moments experienced during FS ascent would have been handled by vectoring of the booster nozzle. After FS booster separation, the US Reaction Control System (ReCS) would have provided the US Element with three degrees of freedom control as needed. The best practices documented in this paper will be focused on the technical designs and producibility of both systems along with the partnership between NASA and Boeing, who was on contract to build the Ares I US Element, which included the FS RoCS and US ReCS. In regards to partnership, focus will be placed on integration along with technical work accomplished by Boeing. This will include detailed emphasis on task orders developed between NASA and Boeing that were used to direct specific work that needed to be accomplished. In summary, this paper attempts to capture key best practices that should be helpful in the development of future launch vehicle and spacecraft RCS designs

Development of a novel Fast-Warm stamping (FWS) technology for manufacturing high-strength steel components

Hot and warm stamping are preferable sheet metal forming technologies used in manufacturing high-strength parts with the twofold objectives of reducing fuel consumption and improving automotive crashworthiness. Great efforts have been made to improve the production rate in these processes and it is difficult to further improve productivity. Therefore, the development of new forming technologies may be an alternative solution to form high-strength steels into complex shapes whilst reducing the cycle time. The present work aims to develop a novel lightweight forming technology, namely fast-warm stamping (FWS) technique, to manufacture high-strength steel components with the desired properties. The concept of this process is to utilise ultra-fast heating of a steel blank to an appropriate temperature, whilst minimising the major negative changes to microstructure which are detrimental to the post-form strength. Mechanical properties such as ductility and post-form strength (PFS) of the MS-W900Y1180T (MS1180) steel were examined via uniaxial tensile tests at various temperatures (25–500°C) and strain rates (0.01–5/s). Special attention has been afforded to the effect of heating rate on thermo-mechanical properties and microstructure of the MS1180 steel with different heating rates. The results suggest that the ductility and post-form hardness of the MS1180 steel were simultaneously improved by 25.7% and 5%, with an increase in heating rate from 1 to 150°C/s. The increased hardness is attributed to the finer precipitated carbides and lower recovery at fast heating rate conditions, which was validated by microstructural observations. The validation of the FWS technology was conducted by forming U-shaped components through a dedicated pilot production line caller Uni-form. The fast-warm stamped components exhibited over 92% mechanical strength of the original as-received material consisting of 1140MPa post-form strength and 370HV hardness. The overall manufacturing cycle time in the FWS process was within 10 seconds. Springback of the formed parts under FWS conditions IV was successfully characterized at various temperatures and forming speeds. Close agreements were achieved between the experimental and simulated results for temperature, thickness distribution and springback prediction of the formed parts which validated the accuracy of the developed finite element (FE) model. FWS technology is a promising solution to manufacture components with desirable mechanical properties and dimensional accuracy. In this work, a feasibility study of the FWS technology was extended from martensitic steels to 60Si2Mn spring steel by producing commercialized disc springs. A separate forming tool set with a replaceable forming surface was developed to reduce manufacturing cost. Experimental results showed that a disc spring was successfully formed using the proposed forming process with the required dimensional precision, post-form strength and surface roughness. This forming technique has shown to enable a tremendous reduction of overall cycle time from 30 minutes to less than 20 seconds and subsequent productivity improvement for a mass-production setting.Open Acces

Deployable Antenna for CubeSat

This project is a proof-of-concept ground model of a large deployable antenna designed for the small space requirements of CubeSats. This small deployment module is designed to fit a 2 m by 1 m reflective antenna inside a storage volume of with the dimensions 20 cm by 20 cm x 40 cm. The reflector will be deployed to a parabolic shape with the goal of modeling the reflector necessary for high frequency communication. Because this module is designed as a proof-of-concept for the deployable parabolic reflector specifically, no electrical components will be incorporated and will just focus on the deployment mechanism and will not be space grade. Because this module is designed as a first iteration, it has the potential to be built upon and improved by other groups in the future

Functional Analysis of Components Manufactured by a Sheet-Bulk Metal Forming Process

Due to rising demands regarding the functionality and load-bearing capacity of functional components such as synchronizer rings in gear systems, conventional forming operations are reaching their limits with respect to formability and efficiency. One way to meet these challenges is the application of the innovative process class of sheet-bulk metal forming (SBMF). By applying bulk forming operations to sheet metal, the advantages of both process classes can be combined, thus realizing an optimized part weight and an adapted load-bearing capacity. Different approaches to manufacturing relevant part geometries were presented and evaluated regarding the process properties and applicability. In this contribution, a self-learning engineering workbench was used to provide geometry-based data regarding a novel component geometry with circumferential involute gearing manufactured in an SBMF process combination of deep drawing and upsetting. Within the comprehensive investigations, the mechanical and geometrical properties of the part were analyzed. Moreover, the manufactured components were compared regarding the increased fatigue strength in cyclic load tests. With the gained experimental and numerical data, the workbench was used for the first time to generate the desired component as a CAD model, as well as to derive design guidelines referring to the investigated properties and fatigue behavior