Encontrados 6 documentos, a visualizar página 1 de 1
Mechanical and surface analysis of Ti0.4Al0.6N/Mo multilayers
Tavares, C. J.; Rebouta, L.; Andritschky, M.; Guimarães, F.; Cavaleiro, A.The quest for hard materials that are able to sustain elevated stresses as tools or cutting processes has led to the investigation of (Ti,Al)N/Mo multilayer coatings. These structures have been deposited by dc magnetron sputtering on high-speed steel and stainless-steel substrates and designed with modulation periods of approximately 13 nm, up to a total thickness of 2.8 [mu]m. Experimental X-ray diffraction (X...
Performance of chromium nitride based coatings under plastic processing conditions
Cunha, L.; Andritschky, M.; Pischow, K.; Wang, Z.; Zarychta, A.; Miranda, A. S.; Cunha, A. M.Chromium nitride based coatings were produced in the form of monolithic and multilayer coatings, by DC and RF reactive magnetron sputtering. These coatings were deposited onto stainless steel and tool steel substrates. Chromium nitride coatings have;proved to be wear and corrosion resistant. The combination of these characteristics was necessary to protect surfaces during plastic processing. In order to select ...
Mechanical characterisation of TiN/ZrN multi-layered coatings
Tavares, C. J.; Rebouta, L.; Andritschky, M.; Ramos, S.Ultra-microhardness, adhesion and residual-stress analysis tests were performed on reactive sputtered deposited TiN/ZrN multi-layers. Hardness values as high as ~3600 Vickers were achieved for this material. Scratch tests of coatings deposited on steel substrates confirmed the existence of different mechanisms associated with total adhesion failure, depending essentially on multi-layer deposition control parame...
Corrosion of TiN, (TiAl)N and CrN hard coatings produced by magnetron sputtering
Cunha, L.; Andritschky, M.; Rebouta, L.; Silva, R. A.Metallic components like moulds, dies and machinery can be subjected to intensive degradation during plastic transformation processes, namely when working with fibre filler materials and plastics which release F, S or Cl during transformation. The degradation is attributed to the combined erosive and abrasive wear by the filler material and corrosive attack of agents. This degradation reduces the lifetime of th...
Structural characterization of microc-si:h films produced by r.f. magnetrons...
Cerqueira, M. F.; Ferreira, J. A.; Andritschky, M.; Costa, Manuel F. M.Microcrystalline silicon thin films were produced by R.F. magnetron sputtering. The microstructure of these films has been studied by X-ray diffraction, transmission electron microscopy (TEM) and Raman spectroscopy. Average values of crystalline size and strain obtained by the different tecnhiques used are critically compared and the reasons for the differences are discussed.
Microcrystalline silicon thin films prepared by RF reactive magnetron sputter d...
Cerqueira, M. F.; Andritschky, M.; Rebouta, L.; Ferreira, J. A.; Silva, M. F.Hydrogenated microcrystalline silicon (microc-Si:H) thin films with Cu as a dopant material (about 2 wt.%) were deposited by RF planar magnetron sputtering in an argon/hydrogen plasma. The composition and microstructure of the films were analysed by SEM, ERD/RBS, X-ray diffraction and Raman spectroscopy. These techniques revealed a columnar film structure, each column consisting of several small (nano) crystals...
| Financiadores do RCAAP | |||||||
|
|
|
|
|
|
||