Climate change and diminishing natural resources are two of the most daunting challenges facing manufacturing industry today. The principal objectives are therefore to reduce costs and to focus on the reduction of energy and resources employed in the production process but also to lower process emissions. A promising approach to gain a significant improvement is the use of lightweight design, which includes the use of lightweight materials and semi-finished products. In many cases, these lightweight materials and semi-finished products are associated with limited processing properties (e.g. machinability and formability) challenging the manufacturer to produce more complex components more efficiently. The increasing requirements in respect of the design and complexity of components as well as flexibility and quality lead to an even more demanding situation. Forming and machining technologies reach their limits as regards feasibility (material behaviour, quality and process forces) and profitability because manufacturing of complex components only becomes efficient with considerable effort in respect of process, tools and machines.
Exploiting the specific velocity effects and using velocity as a decisive parameter in production processes offers diverse opportunities to extend process limits. The present keynote paper focuses on the presentation and exemplification of velocity effects in production processes. The objective is to establish the significance of velocity as a process parameter for today's production engineering by focusing on the relevant processes of forming, shearing, joining and machining. Special emphasis is put on high velocity processes, which are closely related to an increase in profitability due to the production of a greater quantity of components in the same time period. As a result, production costs and energy consumption can be reduced.
Increasing the velocities in the production processes does not only affect profitability but influences the range of application of the process involved. Accordingly, a further emphasis of the keynote paper lies in describing the potential of velocity as a process parameter to influence the technological feasibility, required process forces, process reliability and process stability, achievable quality and for these reasons the extension of process limits. In this regard aspects of high velocity (e.g. high speed cutting) are presented and applications based on low velocities (e.g. superplastic forming) are also discussed.
The term “velocity” covers a broad spectrum of meaning, and the first section of the paper therefore deals with the various interpretations of the term velocity in connection with manufacturing processes. In addition, parameters linked to the velocity are outlined. Subsequently, the effects of velocity on material behaviour and on related forming mechanisms and chip formation mechanisms are analysed and discussed. This also includes the aspects of interface between tool and workpiece and tribological effects. Another aspect which is in the scope of this paper considers velocities in the simulation of processes including a discussion on their characteristics and boundary conditions. Finally, based on examples of different production processes, the effects of velocity on profitability, process performance and quality are presented and the requirements essential for exploiting the resulting potentials are highlighted.