Applicability of different hard coatings in dry milling aluminum alloys

Today, a high proportion of machining processes is conducted with coolants. In this way, the workpiece, tool and machine tool are cooled, friction processes are reduced and the manufactured chips are removed from the cutting area. Unfortunately, coolants are dangerous for the environment and human health. Moreover, the disposal costs for used coolants are going to explode. Therefore, the movement towards green manufacturing cutting operations will be cine of the most Important challenges in the near future. Decreasing the costs of the cutting process and the associated reduction of environmental pollution by dry machining is the main key to remain competitive and profitable. In this contribution, results are presented for the dry milling of an aluminium malleable alloy for aircraft parts (AlZnMgCu1.5) and an aluminium casting alloy for automotive parts (AlSi10Mg). Different commercial coatings were investigated for their suitability in dry milling operations. It is shown that specific coating systems (e.g., partially crystalline hard coatings with ''softer'' morphological parts, or superhard diamond coatings) exhibit a great potential for such operations. However, it should be added that only an iterative development of the whole system (coatings, tool geometry optimization, chip transportation, machine tool adaption, etc.) will deliver a successful implementation of dry processes into production in the near future.