Residual stress, mechanical and microstructure properties of multilayer Mo 2 N/CrN coating produced by R.F Magnetron discharge

Abstract

We have investigated the effect of the period thickness of the multilayer Mo 2 N/CrN deposited on Si substrate produced by reactive magnetron sputtering. Mo 2 N presents a face centered cubic structure and CrN an orthorhombic one. The residual stress of the coatings was determined by the measurement of the substrate curvature. The microstructure of the multilayer was investigated from the X-ray diffraction and scanning electron microscopy (cross section images). The residual stresses resulting from the deposition of the different bi-layer thickness were measured and correlated to the structural properties of the coating as well as the nanoindentation analysis of the coating. The stresses are compressive and tensile for the individual Mo 2 N and CrN layer respectively. The result shows that an increase of the multilayer coatings Mo 2 N/CrN thicknesses induce an increase of the hardness and the elastic modulus, in the other hand the tensile stress increases. The shift of the XRD diffraction peak (1 1 1) of Mo 2 N at high angle which means the reduction of the residual stress is in good agreement with the residual stresses measurements.

Correlation between mechanical and microstructural properties of molybdenum nitride thin films deposited on silicon by reactive R.F. magnetron discharge

“…A tilt of about 10°is observed for coatings (c) and (d), probably due to the target inclination. This is consistent with the working pressure and the target inclination angle [22,44]. This tilt is not seen for the other films, due to the fracture direction of the silicon substrate certainly orthogonal to the column tilt ones.…”

“…(13.56 MHz) reactive magnetron sputtering in an NORDIKO 3500 system as described in a previous paper [22]. The target is a 100 mm diameter disk of pure molybdenum (purity 99.98 at.%).…”

Multilayer design of CrN/MoN protective coatings for enhanced hardness and toughness

“…where n is the Poisson ratio, taken 0.29 both for CrN and MoN [42,51,52]. Larger compressive stress was found for the MoN layer compared to CrN one (see Table 5), which may be due to higher incorporation of nitrogen atoms in the crystal lattice and correlates with the results of elemental composition analysis.…”

Ezerek Parlatma Yapılan AA7075-T6 Alüminyum Alaşımında Meydana Gelen Kalıntı Gerilmelerin İncelenmesi

“…Bu çalışmaların büyük bir çoğunluğu kaynaklı birleştirmelerde meydana gelen kalıntı gerilmeler ile ilgilidir [6][7][8][9]. Diğer bir önemli kısım ise kaplama yöntemlerinin malzeme üzerinde meydana getirdiği kalıntı gerilmeler üzerinedir [10][11][12][13]. Ayrıca ezerek parlatma yöntemi ile ilgili çalışmaların büyük bir kısmı torna tezgâhında silindirik yüzeyler üzerinde özel takımlar kullanılarak gerçekleştirilmiştir.…”