scholarly journals Tribological Performance of PVD Film Systems Against Plastic Counterparts for Adhesion-Reducing Application in Injection Molds

Coatings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 588 ◽  
Author(s):  
Tillmann ◽  
Lopes Dias ◽  
Stangier ◽  
Gelinski

The deposition of physical vapor deposition (PVD) hard films is a promising approach to enhance the tribological properties of injection molds in plastic processing. However, the adhesion is influenced by the pairing of PVD film and processed plastic. For this reason, the friction behavior of different PVD films against polyamide, polypropylene, and polystyrene was investigated in tribometer tests by correlating the relation between the roughness and the adhesion. It was shown that the dispersive and polar surface energy have an impact on the work of adhesion. In particular, Cr-based nitrides with a low polar component exhibit the lowest values ranging from 65.5 to 69.4 mN/m when paired with the polar polyamide. An increased roughness leads to a lower friction due to a reduction of the adhesive friction component, whereas a higher work of adhesion results in higher friction for polyamide and polypropylene. Within this context, most Cr-based nitrides exhibited coefficients of friction below 0.4. In contrast, polystyrene leads to a friction-reducing material transfer. Therefore, a customized deposition of the injection molds with an appropriated PVD film system should be carried out according to the processed plastic.

Author(s):  
Kyriaki Polychronopoulou ◽  
Claus Rebholz ◽  
Nicholaos G. Demas ◽  
Andreas A. Polycarpou ◽  
P. N. Gibson

Cr-N and Cu-Cr-N coatings with Cu content between 3–65 at.%, Cu/Cr ratios in the 0.04–4.5 range and 21–27 at.% N, synthesized by twin e-beam Physical Vapor Deposition (EBPVD) at 450°C, were investigated. Using X-ray photoelectron spectroscopy (XPS), glancing angle X-ray diffraction (GAXRD) and scanning electron microscopy (SEM), in combination with nanoindentation mechanical property measurements and laboratory controlled ball-on-disc sliding experiments, it is shown that Cu-Cr-N coatings with low Cu content (3 at.%) possess sufficient wear resistance for high temperature demanding tribological applications.


Author(s):  
Carl R. Ribaudo ◽  
Chris Aylott ◽  
Dieter Hofmann ◽  
Craig V. Darragh ◽  
Ryan D. Evans ◽  
...  

Scuffing is a severe form of adhesive wear that can occur on gear flanks operating at combinations of high sliding speed and contact stress in marginal lubrication. Engineered Surfaces (ES) refers to the selection, application, and use of certain topographical modification (TM) techniques and thin film coatings applied using advanced physical vapor deposition (PVD) to improve the tribological performance of mechanical components. In this study, the effects of ES technology upon the scuffing resistance of helical gears were empirically determined. Six different treatments of ES technology were tested along with a baseline treatment of uncoated ground surfaces. In the testing, the gear speed was kept constant while the input torque on the gears was incrementally increased until scuffing was observed. Three ES treatments produced statistically significant increases in the scuffing torque relative to the baseline. Increases in mean scuffing torque using ES technology were as high as 89%.


1990 ◽  
Vol 202 ◽  
Author(s):  
C.M. Cotell ◽  
J.A. Sprague ◽  
C.R. Gossett

ABSTRACTThin films of Ag were grown on amorphous C and <111= Si substrates with simultaneous Ar+ bombardment at energies ranging from 50–40,000 eV. For deposition of Ag on amorphous C, ion beam bombardment induced no changes in film nucleation behavior relative to evaporation (henceforth referred to as physical vapor deposition, PVD). Film growth was affected at the highest energy (40 keV); the grain size of the Ag films was increased by a factor of three. Rutherford Backscattering (RBS) measurements on Ag films on <111=Si bombarded with Ar+ at 1.5 keV showed that the Ag sputtering yield at film thicknesses <1.5 nm was less than for bulk Ag, in agreement with TRIM calculations. At 40 keV there was evidence for an additional effect of the ion beam due to recoil implantation or ion mixing. Electron diffraction from Ag fdms grown on <111= Si substrates with simultaneous Ar+ bombardment at either 1.5 keV or 40 keV showed evidence for only the expected phases: single crystal Si, polycrystalline Ag, and an amorphous phase that likely resulted from ion damage to the substrate.


Author(s):  
V. C. Kannan ◽  
S. M. Merchant ◽  
R. B. Irwin ◽  
A. K. Nanda ◽  
M. Sundahl ◽  
...  

Metal silicides such as WSi2, MoSi2, TiSi2, TaSi2 and CoSi2 have received wide attention in recent years for semiconductor applications in integrated circuits. In this study, we describe the microstructures of WSix films deposited on SiO2 (oxide) and polysilicon (poly) surfaces on Si wafers afterdeposition and rapid thermal anneal (RTA) at several temperatures. The stoichiometry of WSix films was confirmed by Rutherford Backscattering Spectroscopy (RBS). A correlation between the observed microstructure and measured sheet resistance of the films was also obtained.WSix films were deposited by physical vapor deposition (PVD) using magnetron sputteringin a Varian 3180. A high purity tungsten silicide target with a Si:W ratio of 2.85 was used. Films deposited on oxide or poly substrates gave rise to a Si:W ratio of 2.65 as observed by RBS. To simulatethe thermal treatments of subsequent processing procedures, wafers with tungsten silicide films were subjected to RTA (AG Associates Heatpulse 4108) in a N2 ambient for 60 seconds at temperatures ranging from 700° to 1000°C.


Biomedicines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 851
Author(s):  
Svetlana I. Dorovskikh ◽  
Evgeniia S. Vikulova ◽  
Elena V. Chepeleva ◽  
Maria B. Vasilieva ◽  
Dmitriy A. Nasimov ◽  
...  

This work is aimed at developing the modification of the surface of medical implants with film materials based on noble metals in order to improve their biological characteristics. Gas-phase transportation methods were proposed to obtain such materials. To determine the effect of the material of the bottom layer of heterometallic structures, Ir, Pt, and PtIr coatings with a thickness of 1.4–1.5 μm were deposited by metal–organic chemical vapor deposition (MOCVD) on Ti6Al4V alloy discs. Two types of antibacterial components, namely, gold nanoparticles (AuNPs) and discontinuous Ag coatings, were deposited on the surface of these coatings. AuNPs (11–14 nm) were deposited by a pulsed MOCVD method, while Ag films (35–40 nm in thickness) were obtained by physical vapor deposition (PVD). The cytotoxic (24 h and 48 h, toward peripheral blood mononuclear cells (PBMCs)) and antibacterial (24 h) properties of monophase (Ag, Ir, Pt, and PtIr) and heterophase (Ag/Pt, Ag/Ir, Ag/PtIr, Au/Pt, Au/Ir, and Au/PtIr) film materials deposited on Ti-alloy samples were studied in vitro and compared with those of uncoated Ti-alloy samples. Studies of the cytokine production by PBMCs in response to incubation of the samples for 24 and 48 h and histological studies at 1 and 3 months after subcutaneous implantation in rats were also performed. Despite the comparable thickness of the fibrous capsule after 3 months, a faster completion of the active phase of encapsulation was observed for the coated implants compared to the Ti alloy analogs. For the Ag-containing samples, growth inhibition of S. epidermidis, S. aureus, Str. pyogenes, P. aeruginosa, and Ent. faecium was observed.


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