Abstract:

The high standards and requirements demanded in high-speed machining (HSM) applications some examples are the precise manufacturing of microelectronics circuits or biomedical devices – comprise a delicate control of the tool preparation as well as coatings design and finish, which are used to extend the operation lifetime of the tool.
The work developed covers the design and deposition of novel coatings focusing on:
a) HiPIMS deposition technology allows the preparation of hard coatings with high smoothness, low density of defects, and good homogeneous coverage of 3D intricate parts (thus able to match the low tolerances required for micromachining), making this technology ideal for these applications. Tested coatings are based on the AlTiN or TiN system, doped with Si or B, which were deposited by HiPIMS on different substrates and on actual milling tools using a semi-industrial sputtering system, attaining hardness values of 35 GPa and good adhesion. Moreover, oxidation studies were performed to determine the thermal stability of these coatings, analyzing, and comparing the results using microstructural and phase characterization tools such as SEM, TEM, and XRD. Observations revealed greater oxidation resistance for the Al containing coatings. Furthermore, a second series of AlTiBN coatings were synthesized in an IMDEA customized sputtering system using conventional DC sputtering for high throughput optimization for the assessment of the effect of B at.% content in the TiAlN lattice.
b) Machining tests, which, in addition to mechanical properties analysis, provide information regarding the performance of the coatings under operation conditions, and the analysis of wear cutting edges in milling tools used for machining Ti6AlV4 alloys.