D.J. Mynors

Applications and capabilities of explosive forming

Abstract All processes, after sufficient time, are visited by a new generation of workers that contemplates process merits and demerits for specific applications. The process that is presently being revisited by academics and industry together is explosive forming. For over 100 years, it has been recognised that explosives can be used in a controlled way in the manufacture of profiled metal components. The required profile results from the explosive force that directly or indirectly deforms the metal. Explosive forming is a broad term covering many process variations. Early patents relating to explosive forming appeared at the end of the 19th and at the beginning of the 20th century. An increasing number of economically successful applications were being seen in the early 1970s, with the manufacture of large aluminium and high strength steel parts. The work presented in this paper results from a global review of activities undertaken in the area of explosive forming, explains the reason for the work, examines explosive forming applications, the associated metallurgy and reviews manufacturing requirements.

Feature extraction from STEP (ISO 10303) CAD drawing files for metalforming process selection in an integrated design system

Abstract This paper addresses a fundamental issue of component manufacture. In particular, it deals with the question of how to get designers to design parts where they may not be familiar with the processes used to manufacture them. The paper describes the development of a CAD linked stand alone computer-based metalforming process module which can be used by design engineers to identify cost effective manufacturing options in conjunction with work reported in [Forming feature representation and process selection in cold extrusion, in: Proccedings of to the Ninth International Conference on Metal-Forming, Birmingham, UK, 125–126 (2002) 456–463].

Controlling the Cold Roll Forming Design Process

The cold roll forming process requires successive forming profiles to be determined and an appropriate number of profiled roll sets to be designed for the product to be rolled. This paper examines the design process and how one company has put in place a design-production control system that allows designs to be ranked in terms of quality and efficiency. In addition, consideration is given to the proportion of time given to each design task and how non-creative design activities can be automated.

A National Centre for Metalforming Simulation in the UK

Abstract This paper examines the unique work being undertaken in the UK to ensure the continued competitiveness and advancement in capabilities of the companies that make up the UK metalforming industry. The work is a partnership between commercial metalforming simulation package vendors, universities and the industry through its main trade association the Confederation of British Metalforming. In examining the present activities, a case is made for a National Centre for Metalforming Simulation.

A fast new numerical tool for designing prestressed dies for backward extrusion: Part 2: Numerical analysis

Abstract The economics of forging requires tools to be designed to ensure maximum service life. Ideally, this should be achieved by determining the maximum equivalent stress experienced by tools during service. However, the determination of the maximum equivalent stress in the dies through numerical simulations is very time consuming. For the case of a backward extrusion process, this paper proposes a method for its determination that is based on an analytical function of the process parameters. This function was obtained by generating a database that includes the maximum equivalent stress for a large range of process parameters. This database was then modelled by a function determined through statistical analysis.

The management of expert knowledge for cold roll form design

This paper describes issues relating to the Knowledge Management (KM) of expert roll tool design, as part of an initiative to improve the design process for cold roll forming. The management of knowledge has been used to standardise design practices in working towards automation, to improve lead times and retain expert knowledge within a metal forming organisation. The paper utilises the first two years of a real and ongoing 4-year case study, to examine KM and Knowledge Elicitation (KE) initiatives and specific problems experienced during the management of expert knowledge.

Forming feature representation and process selection in cold extrusion

Abstract This paper presents a conceptual classification of geometric shapes and a representation of process-oriented forming features in cold extrusion to develop a process selection module for a generative CAPP system in metalforming. The output of the module provides extrusion process options to produce the forming features of components and an evaluation of the formability of the forming features.

A fast new numerical tool for designing prestressed dies for backward extrusion: Part 1: Die behaviour

Abstract Prestressed die inserts are often used in the forging of axisymmetric parts. Their use enhances overall tool economy and can enhance the quality of the finished forging. The design of tooling that incorporates prestressed die inserts is, however, complex. The complexity arises from the interrelated phenomena that occur within the dies during the forging process. As a result, it is not possible to obtain an analytical expression for critical parameters such as die stresses and deflections. This paper shows the limitations of currently used design methods, and identifies, for the backward extrusion process, which physical phenomena should be taken into account when designing prestressed tooling.

Quantifying Experiential Design and Knowledge in the Tool, Die and Mould Industry

The design of components, manufacturing processes, associated equipment and tooling is frequently dependent on the experience and skills of individuals. Researchers and industrialists rarely, if ever, dwell upon or try to quantify the experience or knowledge state of a company. This paper considers the type of knowledge and experience that can exist in companies that design, make, and/or use tools, dies, or moulds; this paper also proposes a knowledge coding system as the basis for future benchmarking development.

Increasing yield during the manufacture of semi-finished extruded products

Abstract This paper reviews work presently being undertaken in an attempt to increase the yield figures of a major extruder. The manufacturing process is concerned with the process that converts raw materials into semi-finished products and the support functions associated in fulfilling that task. The examination allows the determination of yield figures. The paper then goes on to report the application of a Pareto analysis to identify those alloys and production routes that resulted in low overall yields. With the low yield manufacturing routes identified the mechanisms of enhancing the yields and their success are considered and tested.