Advanced materials are crucial for the development of many industrial sectors such as aerospace, automotive, energy, among others. These materials show superior mechanical characteristics of strength, hardness, toughness, and durability in comparison to conventional materials. However, these materials are also characterized by their complicated primary processes (e.g., casting or forge) and the secondary processes (e.g., machining) because of their low machinability.
In addition, the development of new advanced materials requires the use of advanced manufacturing technologies supported on new and high-quality machine tools. In this decade, machine tools are becoming multitasking systems, that is, a combination of milling centers, lathes, and even grinding machines. Thanks to computer numerical control (CNC), users are able to interpolate and synchronize several machine axes, as well as find new mechanical solutions for transmissions based on direct hollow motors, or linear guided ones, including lineal motors. Machine tools are particularly stiff spatial manipulators, in order to achieve tolerances reaching an order of magnitude in the hundredths.
New processes and new cooling systems, tools, and coatings must be investigated to enable the machining of these advanced materials. Machines that apply the processes can be also improved by introducing new components, control approaches, and monitoring and recording systems. The concept of digitalization in the global industry 4.0 is now a hot topic, including the use of artificial intelligence utilities [1].
This Special Issue includes works that present new forming and machining processes used on special steels and titanium alloys, define machine precision using a new metrology approach, and give some ideas about how to improve machinability by adding small amounts of chemical elements to steels.
It is difficult to propose an up-to-date classification of machine tools, a task made even more difficult after the introduction of additive manufacturing in workshops. Table 1 proposes a new classification, based on a previous one given in [2].
Table 1.
Current classification of machine tools.
Conflicts of Interest
The authors declare no conflict of interest.
References
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- López de Lacalle, L.N.; Lamikiz, A. Machine Tools for High Performance Machining; Springerg: Berlin, Germany, 2009. [Google Scholar]
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