Microstructure and physical properties of arc ion plated TiAlN/Cu thin film

Multilayered TiAlN/Cu coatings were produced by using a cathodic vacuum arc (CVA) deposition system. Filter was incorporated to the system in order to get rid of oversized particles. The TiAlN layer gives a columnar structure. If the TiAlN deposit was interrupted periodically by adding copper to its composite, TiAlN/Cu nanomultilayer structure formed. Which can be clearly observed through high-resolution transmission electron microscopy (HRTEM), and the thickness of periodic nano-laminates of TiAlN in composite TiAlN/Cu coatings is approximately 7–8 nm. EDS analysis showed the copper content in TiAlN/Cu specimen is only about 4.5 at.%, yet it brings significant influence to the film composition, in which the titanium is suppressed while the aluminum is increased.By adding copper to TiAlN, the electron diffraction patterns were changed from spotty ring to continuous indicating the formation of nanocrystalline structure in TiAlN/Cu multilayered coating. The oxidation resistant temperature of TiAlN coating is examined at about 868.8 °C, and decreased to about 855.7 °C after adding copper in the coating. The nanoindentation measurement of TiAlN/Cu multilayered coated material shows a higher elastic modulus of about 361 GPa than that of TiAlN about 348 GPa, but a lower hardness of about 24 GPa than that of TiAlN about 30 GPa.