Objective
The "problem solving" of this proposal is to replace the presently used coolant machining (of cold working tool materials) and stamping (of metallic materials) technologies based on synthetic lubricants by technologies based on lubricant-free machining and stamping, with a strong decrease of dies construction and use costs, and a large environmental impact. The industrial objective of this project is to develop dry or nearly dry stamping operation of different metallic materials, and dry machining operations of different "difficult to-cut" metallic materials with innovative Superhard Nanocomposite coated dies, mould and cutting tools.
Definition of industrial requirements,: machining operations : CRF selected within Fiat Group possible application of nanocomposite coatings, focusing on the core activity of the project: machining of dies materials. Definition of industrial requirements : stamping operations : Gammastamp e Genta : The first information obtained is about zones of the tools surface we have to treat in order to increase the wear resistance. The second information obtained is the number of components that the coated tools are able to produce between two maintenance stops. This permits a more effective maintenance planning with money and time saving.
-Base development of the novel superhard nanocomposites coatings:
-Modified PVD coating unit was used for preparation of improved nc-(Ti1-xAlx)N/a-Si3N4 coatings. Coatings have better uniformity and lower roughness below 0,1 µm.
-Modification of the coating unit suitable to operate in combined mode PACVD/PVD was finished. A series of deposition experiments with superhard Ti-B-N coatings deposited in industrial coating equipment at SHM and their characterization by ICIM were done. Coatings have the composition TiN1-x/a-TiB2, roughness below 0,15 µm and hardness above 60 Gpa;
-ICIM developed nc-TiN/a-BN and nc-TiN/a-BN/a-TiB2 superhard nanocomposite coatings that reach hardness of 50 GPa and are promising candidate for self-lubricant coatings that will be able to operate at much higher temperature (550 C) than the presently available DLC, MoS2 and others can;
-Nanocrystalline composite coatings were deposited on the wide range of HSS and HM substrates for physical characterisation and testing of application. Coatings have high hardness above 35 or 40 GPa, very good adhesion and low friction coefficcient below 0,7;
-Design work of the new arrangement of electrodes (targets) according to the preliminary results LARC and Virtual Shutter SHM & PLATIT is a great achievement.
Industrial development of new superhard nanocomposite coatings by SHM concentrated on two systems: nc-(Ti1-xAlx)N/a-Si3N4, "MARWIN", which was developed as a single-layer and multi-layer coating and the nc-Ti-B-N coatings. In particular:
-Ti-B-N Superhard (³ 60 GPa), coatings prepared by Vacuum Arc Technology;
-nc-TiN/a-Si3N4/a- & nc-TiSi2 nanocomposites ternary and quaternary ultrahard coatings (HV " 80-100 GPa) deposited at the cathode of abnormal DC glow discharge with TiN Nanocrystals Imbedded in the Amorphous Matrix;
-nc - (Ti1-xAlx)N/a-Si3N4 Nanocomposites deposited by vacuum arc evaporation at SHM Ltd, with Thermal stability up to ³ 1.100 C;
-Ultrahard Ternary nc-TiN/a-Si3N4/a-TiSi2 Nanocomposites coatings with Thermal stability up to ³ 800 C and Hardness slightly increases upon annealing to 70 - 80 Gpa, but they present a degradation in air after 5 months or more time.
-Characterisation of coated samples : The standardization of the hardness measurement was done in collaboration between ICIM and SHM by exchanging samples with hardness of ³ 40 GPa for the measurements and in course of several visits of the researchers on the site of the partners.
-ICIM has identified and investigated in detail a number of possible artefacts that falsify the values of hardness obtained by the automated load-depth indentation technique. Experimental procedures that avoid such erroneous measurements were developed and made available to the project partners as well as to scientific community.
-A decisive progress has been done towards the understanding of the properties of the new nanocomposite coatings and their basic characterization. This has been achieved by a collaboration between ICIM, SHM and Messachusetts Institute of Technology. SHM provided nc-(Ti1-xAlx)N/a-Si3N4 samples deposited by the industrial coating technology. The nc-TiN/a-Si3N4, nc-TiN/a-Si3N4/a- & nc-TiSi2, nc-TiN/a-BN and nc-TiN/a-BN/a-TiB2 coatings prepared at ICIM were used for the verification of the generic concept for the design of the superhard nanocomposites with a high thermal stability.
-ICIM developed a new coating technology by reactive magnetron sputtering with central electrode that allows us to obtain superhard nanocomposite coatings in a prototype of an industrial scale reactor.
-Optimisation of coating technologies: The optimization of the available laboratory plasma CVD equipment was done ahead of the plan in order to be able to speed up the development and study of the coatings.
-Industrial exploitation of developed coatings in the dry machining of difficult to cut materials for dies (aluminium alloys, etc.). Due to the good performance of the coating experimentations has been extended also to the machining of other materials for automotive components.
Conclusions after the mid term point:
1.The superhard nc - (Ti1-xAlx)N/a-Si3N4 nanocomposites based on that generic design principle are stable up to high temperatures of 1100 C.
2.Then analysis of the indentation curves in terms of Hertzian elastic response confirms the high elasticity and shows that the superhard nanocomposites are indeed strong materials.
3.The unusual combination of their high hardness and high elastic recovery can be understood in terms of conventional fracture mechanics scaled down to dimensions of few nanometer small nanocrystals.
4.The high resistance against crack formation is a consequence of a low concentration of flaws which is a result of the 'selforganization" of the nanostructure due to thermodynamically driven segregation, a very small stress concentration factor of 2 - 4 and very frequent deflection and branching of few nanometer small nanocracks.
5.The reversible flexing explains in a simple way the high elastic energy density and elastic recovery.
6.The strong enhancement of the elastic modulus measured by the indentation is probably due to very high pressure under the indenter during the measurement. Extreme care should be exercised to prove that a superhardness in thin coatings is their intrinsic property and not falsified by a high compressive stress.
Fields of science (EuroSciVoc)
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
- engineering and technologycivil engineeringstructural engineeringstructural health monitoring
- engineering and technologymechanical engineeringmanufacturing engineeringsubtractive manufacturing
- engineering and technologynanotechnologynano-materialsnanocrystals
- engineering and technologymaterials engineeringcoating and films
- engineering and technologymaterials engineeringnanocomposites
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Keywords
Call for proposal
Data not availableFunding Scheme
CSC - Cost-sharing contractsCoordinator
10040 CASELETTE
Italy