Structure And Properties Of PVD Coatings Deposited On Cermets

Abstract

The main aim of the research is the investigation of the structure and properties of single-layer and gradient coatings of the type (Ti,Al)N and Ti(C,N) deposited by physical vapour deposition technology (PVD) on the cermets substrate.The structural investigations include the metallographic analysis on the transmission and scanning electron microscope. Examinations of the chemical compositions of the deposited coatings were carried out using the X-ray energy dispersive spectrograph EDS, and using the X-ray diffractometer. The investigations include also analysis of the mechanical and functional properties of the materials: substrate hardness tests and microhardness tests of the deposited coatings, surface roughness tests, evaluation of the adhesion of the deposited coatings as well as cutting properties.The results of the investigations carried out confirm the advantages of PVD coatings deposited onto cermets substrate especially in case of (Ti,Al)N. Coatings deposited onto the investigated substrates are characterised by good adhesion, high microhardness, taking effect in very high increasing of wear resistance.Deposition of hard, thin, gradient coatings on materials surface by PVD method features one of the most intensely developed directions of improvement of the working properties of materials. Equally important is the development of tool materials with respect to the fabrication of thin coatings resistant to wear in PVD process. It is of considerable importance, since through the selection of appropriate components, we can obtain a tool material of better properties. This area of tool material development is a priority nowadays, since it is the main route leading to the acquisition of machining tools of suitable properties.The results of the investigation provide useful information on microstructure, adhesion characterized in a scratch test, wear resistant properties of the gradient and single-layer coatings deposited onto cermet.Keywords: Tool materials, Gradient coating, Cermets, PVD Celem artykułu było zbadanie struktury i właściwości jednowarstwowych i gradientowych powłok typu (Ti,Al)N oraz Ti(C,N) naniesionych metodą fizycznego osadzania z fazy gazowej (PVD) na podłożu z cermetali narzędziowych.Badania strukturalne obejmują transmisyjną i skaningową mikroskopię elektronową. Analizę składu chemicznego i fazowego badanych powłok wykonano metodą spektroskopii energii rozproszonego promieniowania rentgenowskiego (EDS) oraz metodą dyfrakcji rentgenowskiej za pomocą dyfraktometru rentgenowskiego. Badania obejmują również analizę właściwości mechanicznych i funkcjonalnych badanych materiałów: badanie twardości podłoża z cermetalu i testy mikrotwardości naniesionych powłok, badania chropowatości powierzchni, ocena przyczepności naniesionych powłok, jak również właściwości skrawne.Wyniki przeprowadzonych badań potwierdzają zalety powłok PVD osadzanych na podłożu z cermetalu, zwłaszcza w przypadku powłok typu (Ti,Al)N. Powłoki osadzone na badanych podłożach charakteryzują się dobrą przyczepnością, wykazują wyso...

Wear Resistance of (Ti,Al)N Metallic Coatings for Extremal Working Conditions

“…In case of cemented carbide and cermet substrates, crater wear was significantly decreased after coating deposition, mostly as a result of diffusion and abrasive wear protection (Figure 6c). This has been confirmed by results obtained earlier by the authors, and results of other tests of functional properties carried out for this group of coatings [9][10][11][12][13][14][22][23][24].…”

“…In case of cemented carbide and cermet substrates, crater wear was significantly decreased after coating deposition, mostly as a result of diffusion and abrasive wear protection (Figure 6c). This has been confirmed by results obtained earlier by the authors, and results of other tests of functional properties carried out for this group of coatings [9][10][11][12][13][14][22][23][24]. In case of Al2O3 based ceramics (of low chemical affinity to Fe and high chemical stability), the diffusion wear is very low and characteristic uniform wear of tools with small craters was observed for uncoated tools as well for coated tools (Figure 6b).…”

“…Coatings present a characteristic columnar, fine-graded structure and adhere tightly to the substrates (Figure 1). The structural and tribological advantages of the (Ti,Al)N coating have been described in previous works of the authors [11][12][13][14] and in cited papers [18][19][20]. The roughness, R a , parameter measured for substrates is within the range of 0.07 µm in case of cermet substrate to 0.24 µm in case of Al 2 O 3 ceramics reinforced with SiC whiskers.…”

“…Tool application of (Ti,Al)N coating increases wear resistance and eliminates a number of limitations and drawbacks observed in the use of TiN and Ti(C,N) coatings [9,10]. This article is a continuation of the research conducted by the authors in the field of increasing the functional properties of cutting tools [3,4,[11][12][13][14][15].…”

Investigation studies involving wear-resistant ALD/PVD hybrid coatings on sintered tool substrates

“…The coating of ceramic materials in PVD processes, including also tool ceramics, is difficult due to dielectric properties, since the inability of the substrate polarization during the coating process makes it difficult to obtain coatings with a good adherence to ceramic substrates. 2,[7][8][9][10][11] The fabrication technology of stratified coatings of the type "adhesive layer/PVD layer" using the multistage surface machining is one of the most modern methods to modify the properties of the surface layer and it consists, in a successive application, of two (or more) technologies of surface engineering. In terms of material effects, we obtain multilayer systems whereof one part is made up of an appropriately selected adhesive layer fabricated on the surface of the substrate, which protects the "proper" PVD layer against a loss of internal cohesion and an insufficient adhesion to the substrate.…”