Microstructure evaluation and mechanical properties of nanolayered chromium nitride/tungsten nitride coating

Severe plastic deformation processes like equal channel angular extrusion (ECAE) have been widely investigated for their ability to produce nano/ ultra fine-grained microstructures. It is well known that submicron sized grains/ sub grains can be produced in most Al alloys using this technique. However, industrial applications of ECAE will depend heavily on the advantages conferred by this process when it is used as an intermediate processing step prior to conventional forming. In the current investigation, the influence of pre processing by ECAE on subsequent post processing by conventional cold extrusion has been investigated. ECAE extrusion was carried out on cylindrical specimens of AA 6101 using an ECAE die with a die angle of 120 degrees. Extrusion was carried out for three passes using two different processing routes. The ECA extruded specimens were subsequently subjected to conventional cold extrusion. The differences in extrusion pressures, which have a strong influence on industrial applications, were noted. Changes in microstructure and mechanical properties were also determined. The obtained results of mechanical properties and microstructure evaluation show that for high strains (strain ε ≈ 2.01), ECAE through some processing routes can be effectively used as an intermediate processing step prior to conventional cold extrusion to obtain a product with enhanced mechanical properties.

Download Full-text

Investigation on the structural and mechanical properties of anti-sticking sputtered tungsten chromium nitride films

Thin Solid Films ◽

10.1016/j.tsf.2012.09.036 ◽

2013 ◽

Vol 529 ◽

pp. 333-337 ◽

Cited By ~ 17

Author(s):

Tai-Nan Lin ◽

Sheng Han ◽

Ko-Wei Weng ◽

Chin-Tan Lee

Keyword(s):

Mechanical Properties ◽

Chromium Nitride

Download Full-text

Chrome nitride coating reduces wear of small, spherical CrCoMo metal-on-metal articulations in a joint simulator

Journal of Hand Surgery (European Volume) ◽

10.1177/1753193416674161 ◽

2016 ◽

Vol 42 (3) ◽

pp. 310-315

Author(s):

R. Thorkildsen ◽

O. Reigstad ◽

M. Røkkum

Keyword(s):

Weight Loss ◽

Chromium Nitride ◽

Nitride Coating ◽

Volumetric Wear ◽

Carpometacarpal Joint ◽

Joint Replacements ◽

Ringer’S Solution ◽

Metal On Metal

Metal-on-metal articulations have fallen out of favour in larger joint replacements, but are still used in smaller joints. Coating the articulation has been suggested as one way of reducing wear. We compared a standard 6 mm CrCoMo articulation designed for the carpometacarpal joint of the thumb with a chromium nitride-coated version after 512,000 cycles in a joint simulator. A total of 6 articulations in each group were tested with a unidirectional load of 5 kg in Ringer’s solution. We found a statistically significant reduction in weight loss, amount of metallic wear produced and volumetric wear for the chromium nitride-coated articulation. Our findings support the use of chromium nitride coating in order to minimize the amount of metallic wear produced.

Download Full-text

Microstructural and Mechanical Properties of Nanostructured Tungsten Nitride Thin Films Prepared by RF Reactive Magnetron Sputtering

Advanced Science Letters ◽

10.1166/asl.2018.12212 ◽

2018 ◽

Vol 24 (8) ◽

pp. 5872-5876

Author(s):

G Balakrishnan ◽

V Sathiyaraj ◽

M Dinesh ◽

P. Naveen Chandran ◽

C Thamotharan

Keyword(s):

Thin Films ◽

Mechanical Properties ◽

Magnetron Sputtering ◽

Nitrogen Content ◽

High Hardness ◽

Reactive Magnetron Sputtering ◽

Tungsten Nitride ◽

Reactive Magnetron ◽

Microstructural Property ◽

Steel Substrates

In the present work, nanostructured tungsten nitride (WN) thin films were deposited by RF reactive magnetron sputtering technique in a mixture of N2 and Argon atmosphere and its microstructure and mechanical properties were investigated. The Argon pressure was kept constant at 20 sccm, while the N2 partial pressures were varied (3%, 5%, 10% and 15%). The WN thin films are deposited on SS304 stainless steel substrates at a temperature of 500 °C. The microstructural property was analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) and mechanical properties were evaluated by nanoindentation technique. The XRD studies indicated the formation of different phases as a function of nitrogen content. The hardness and the young’s modulus values were in the range 27–39 GPa and 239–280 GPa, respectively. The high hardness values correspond to the coatings with the low nitrogen content and vice-versa. The mechanical properties of the tungsten nitride coatings were strongly influenced by the microstructure.

Download Full-text

Comparison of microstructure and mechanical properties of chromium nitride-based coatings deposited by high power impulse magnetron sputtering and by the combined steered cathodic arc/unbalanced magnetron technique

Thin Solid Films ◽

10.1016/j.tsf.2003.11.113 ◽

2004 ◽

Vol 457 (2) ◽

pp. 270-277 ◽

Cited By ~ 171

Author(s):

A.P Ehiasarian ◽

P.Eh Hovsepian ◽

L Hultman ◽

U Helmersson

Keyword(s):

Mechanical Properties ◽

Magnetron Sputtering ◽

High Power ◽

Chromium Nitride ◽

Microstructure And Mechanical Properties ◽

Unbalanced Magnetron ◽

Cathodic Arc

Download Full-text

Mechanical Properties and Microstructures of Narrow Gap Orbital Welded P91 Steel

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.258.635 ◽

2016 ◽

Vol 258 ◽

pp. 635-638 ◽

Cited By ~ 1

Author(s):

Michal Junek ◽

Marie Svobodová ◽

Jiří Janovec ◽

Jakub Horváth

Keyword(s):

Mechanical Properties ◽

Weld Metal ◽

Base Metal ◽

Heat Affected Zone ◽

Room Temperature ◽

Tensile Specimen ◽

Narrow Gap ◽

P91 Steel ◽

Microstructure Evaluation ◽

The Individual

This article deals with the results of mechanical testing and structural analysis of sections of narrow gap orbital welded P91 steel on tube OD 355.6 x 40 mm. The evaluation of mechanical properties was based on tensile test at room temperature on mini-tensile specimens and on measurement of modulus of elasticity. Weld was cut longitudinally into 9 narrow slices by using waterjet. From these slices 108 flat mini-tensile specimens (dimensions of gauge is 2 x 2 mm) were prepared. In experimental part microstructure evaluation and documentation of fracture surface of each mini-tensile specimen were carried out. The aim of these experiments was to assess the mechanical properties of the individual sections of the weld (base metal, heat affected zone and weld metal). These data can be used for new approaches of FEM modelling of welds considering heat affected zone like a combination of different materials with different mechanical properties, which connect the thermally unaffected base metal and weld metal.

Download Full-text

Mechanical Properties of La2O3-Al2O3 Ceramics Prepared by Microwave Sintering

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.519.265 ◽

2012 ◽

Vol 519 ◽

pp. 265-268 ◽

Cited By ~ 1

Author(s):

Yun Long Ai ◽

Fei He ◽

Bing Liang Liang ◽

Wen He ◽

Wei Hua Chen

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Draw Ratio ◽

Sintering Temperature ◽

Microwave Sintering ◽

Microwave Energy ◽

Pure Alumina ◽

Sintering Time ◽

Microstructure Evaluation ◽

Columnar Grains

The influence of La2O3 on the phase and microstructure evaluation and mechanical properties of La2O3-Al2O3 ceramics sintered with 2.45 GHz microwave energy was investigated. The results showed that La2O3 could densify the pure alumina with a lower sintering temperature and a short sintering time. La2O3 reacted with Al2O3 to form LaAl11O18 completely and the amount of LaAl11O18 increased with the increasing content of La2O3, distributing at the Al2O3 grain boundaries. The specimen doped with 10 vol.% and 15 vol.% La2O3 sintered at 1500 °C exhibited plenty of columnar grains with draw ratio about 1:4. The existence of columnar grains enhanced the microhardness and fracture toughness of La2O3-Al2O3 ceramics.

Download Full-text