Manufacturing Processes

To gain competitive advantages in their markets, industrial companies must develop and maintain the ability to manufacture products that not only comply with strict quality requirements but that are also cost-effective. In order to achieve this, they need to stay at the leading edge of manufacturing technologies either by improving their processes, acquiring new available processes or even developing new processes. Each of these strategies calls for in-depth knowledge regarding the way in which technologies are evolving and how process innovations impact on everyday manufacturing practice.

The design, test and implementation of solutions for future manufacturing requirements is the overall goal of this research group. Targeted studies on specific industrial problems are often carried out in collaboration with partner companies and considerable know how has been acquired on several manufacturing processes and applications, including conventional and unconventional material removal techniques, additive manufacturing, metal forming, joining and welding, surface treatments, mechanical de-manufacturing and recycling. The majority of group activities is focused on several main research areas. These include (a) basic research regarding the physical phenomena governing manufacturing processes, (b) applied research devoted to the implementation of new technologies in an existing processing chain and (c) the development, characterization, monitoring and diagnosis of machine tools.

As regards basic research, the quality and performance parameters of processes are investigated by means of laboratory tests in order to relate them to process variables. This allows for the building of extensive process knowledge, from which "technological operating windows" can be readily derived for an optimal tuning of the processes at the shop floor. Examples of such achievements include the modeling of tool wear, residual stresses, defects of surface integrity, loss of accuracy due to cutting kerfs and burrs. These and other specific issues are investigated for both conventional processes for new or difficult-to-work materials (such as cellular metal, hybrid materials, advanced composites, high strength alloys) and unconventional processes such as laser beam processing, plasma arc and water jet machining, micro-machining and additive manufacturing. The combination of a number of different technologies in one process chain is often studied in order to exploit related strengths and develop hybrid manufacturing solutions.

Applied research deals with challenging industrial cases, where the limitations of current solutions require new approaches based on unconventional processes. A short list of case histories highlights a wealth of unusual applications currently being explored in the group's laboratory using state-of-the-art machinery: water jet and laser cutting on composite and other difficult-to-machine materials; fiber laser for cladding of high resistance products like gas turbine engine blades; ultrasonic welding for thin parts in aluminium and magnesium; hybrid processes based on adhesive bonding and ultrasonic welding for difficult-to-weld materials such as magnesium; diode lasers for surface hardening in situations where accessibility is a problem; water jet and fiber laser to drill titanium and magnesium alloys for aerospace and medical applications; metal foaming for lightweight structures that have stiffness and vibration damping requirements; five-axis micromachining for high precision parts such as bio-absorbable stents, micro-actuators and micro-fuel cells; FEM simulation of metal forming processes.

Machine tools are another area where design and experimental knowledge is acquired using the most updated methods. An improved use of existing machines is made possible by defining their proper operating range in order to avoid chatter and other stability problems and to enhance the energetic efficiency of machine tools and production systems. Innovative machine concepts and subsystems have been developed (and often patented), including an abrasive dosing system and an additive injection system for water jet cutting, a steel deposition method for nitrided metal parts, an optimized pre-stressed design for high tonnage press frames. As a further application of machine tool knowledge, monitoring systems for advanced statistical process control and diagnostics, based on typical signal profiles for process variables (current, force pressure, power, temperature and others depending on the specific process), are developed.