Incipient plasticity of CVD Al2O3/TiCN multilayer coatings during nanoindentation
|Coordinator||Lunds universitet - Institutionen för Maskinteknologi Industriell Produktion|
|Funding from Vinnova||SEK 407 000|
|Project duration||August 2019 - August 2021|
|Venture||Research infrastructure - utilisation and collaboration|
|Call||Industrial pilot projects for utilisation of neutron- and photon based techniques at large scale infrastructures - spring 2019|
Purpose and goal
The purpose of the project is to characterize the mechanical and structural change of CVD coatings under load. This by adapting an nano-indentation instrument to be used in in-beam experiments at synchrotron facilities. The possibilities to conduct a detailed in-situ characterization of the mechanical behaviour and structural evolution of thin CVD coating layers at the microscale would allow Seco Tools to obtain deeper knowledge that can be used to design and optimize coating materials with enhanced properties to achieve a predictable performance in metal machining applications.
Expected results and effects
The results from time resolved synchrotron diffraction measurement with high spatial resolution (100 nm) will permit the evolution of elastic strains and related internal stresses in the individual coating layers to be measured with great accuracy. Such results can be utilized at Seco to systematically evaluate the role of the composition of coating material (microstructure, grain size, crystallographic orientation) and coating architecture (single, multilayer) on its mechanical response. The results can be implemented in an IT-based system at Seco to be used by R&D engineers.
Planned approach and implementation
Ssubstrates will be coated by Ti(C,N)/Al2O3 using CVD, with different texture for different samples. The initial state (microstructures, stress, thickness) will be studied using XRD and EBSD. Lamellae will be prepared from these samples using mechanical polishing and focus ion beam (FIB). The lamellae will be subjected to wedge indentation (force up to 0.5 N using a diamond wedge) while synchrotron diffraction data is collected at NanoMAX beamline. From the data, maps of changes in chemistry and elastic strain and stress can be computed. Complementary, TEM will also be conducted.