Skip to main content

Duplex based diamond coatings for cutting tools

Objective


CRF (JRC subcontractor) have developed and supplied several CVD coating Tungsten based, and Genta supplied the PVD ones Titanium based. In the month 18, the Consortium had to avoid using the intermediate layer because of the poor results obtained. The end user (Recoules and Novatea) supplied several tailor made substrate to be coated.
Moreover, CRF has analysed all the coating (Ti, W, and diamond) in order to select the better material solution for tool application. A large number of diamond insert from the Dico project as from different suppliers were analysed in order to compare and to update the state of the art.
CNRS, with the help of ICMC, has a central rule in optimise the diamond coating technologies. Large number of parameters as substrate were tested and at the end, the last coating had very important results.
Concerning the HSS items, The Consortium had to avoid these task that aimed on coating with diamond the HSS, because of the time and the efforts focused on coating HM substrates.
CNR-ILM has tested the different coatings supplied by CNRS. Two kind of material were machined by these innovative tools: hypereutectic Al alloys and MMC alloys. Moreover a few tests were carried on Al alloy in order to give an idea of the tool life of these tools in a real production.
There is an increasing demand to use new workpiece materials such as the difficult-to-cut metal matrix composite materials e.g. aluminium silicon carbide composites and SMC (epoxy resin reiforced with glass fiber). A solution for the machining of these materials is the use of diamond coated tools. However at the present time diamond coatings on 3-dimensional tools such as milling tools are not yet fully developed. Although a market pull does exist for these coatings any many projects are aiming at the development of diamond coatings on tools no valid technological solution is available. Indeed only simple geometry is coatable and often no sufficient diamond coating adhesion is obtained. Due to these facts it is necessary to develop new diamond coatings which allow to coat relative complex geometry with an adherent diamond coating. Furthermore since it is not feasible to coat high speed steel (HSS) and hard metal (HM) which contains more than 5% cobalt it is necessary to increase the now small range of diamond coatable substrate materials The RTD targets of DICO are: *to develop innovative plasma pre-treatments and intermediate layers deposited with PVD and/or PACVD techniques in order to optimise the adhesion of diamond coatings on hard metal (HM) and high speed steel (HSS) cutting materials: 'duplex coating technology'; *to develop an innovative microcrystalline diamond (grain size: 30-200nm) PACVD coatinq technology in order to optimise the cutting tool performances in high speed dry machining of difficult-to-cut materials (e.g. Al-based metal matrix composites ); *to redefine the geometry of HM and HSS cutting tools in order to use full the performance of diamond coated tools, and to increase the performance of the coated tools; *to optimise the drv machining of metallic non-ferrous alloys and of wood based materials for different cutting tool operations. By carrying out the R&D work the acquired fundamental knowledge will lead to an understanding of the complex relationships between deposition process parameters, microstructure of the coating and its functionality. The final result of DICO will be the tuning up of a complete optimised procedure for the coating of HM and HSS cutting tools with a duplex coating technology consisting of an intermediate layer and a microcrystalline diamond coating.

Funding Scheme

CRS - Cooperative research contracts

Coordinator

TRATTAMENTI TERMICI FERIOLI E GIANOTTI SPA
Address
1-3,Via E. Fermi 1-3
10040 Caselette
Italy

Participants (7)

CENTRO RICERCHE FIAT S.C.P.A
Italy
Address
50,Strada Torino, 50
10043 Orbassano
COMMISSION OF THE EUROPEAN COMMUNITIES
Netherlands
Address
Westerduinweg 3
1755 ZG Petten
Centre National de la Recherche Scientifique
France
Address
Avenue Jean Baptiste Clément
93430 Villetaneuse
Innovations Couches Minces SA
France
Address
Rue Robert Schuman
77350 Le Mée Sur Seine
NATIONAL RESEARCH COUNCIL OF ITALY
Italy
Address
127,Via Frejus 127
10043 Orbassano
NOVATEA SPA
Italy
Address
Strada Trossi 41
13871 Verrone
Recoules SA
France
Address
Rue Maurice Chevalier
77831 Ozoir La Ferrière