Duplex surface treatment of moulds for pressure casting of aluminium

“…In addition, due to their chemical inertness, PVD coatings are very well suited for resisting corrosion [10][11][12][13][14] . Some typical application examples of duplex surface treatments may be found in forming dies, casting molds, cutting tools and prosthetic implants [15][16][17][18][19][20] . Abrasive wear resistance is a key aspect in duplex-treated surfaces.…”

Section: Introductionmentioning

confidence: 99%

Micro-Scale Abrasive Wear Testing of CrN Duplex PVD Coating on Pre-Nitrided Tool Steel

et al. 2017

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Specific wear rates were calculated from a series of micro-scale abrasive tests by means of the calotte-grinding method. The tested material was a CrN coating deposited by arc evaporation on ionnitrided AISI H13 steel. Characterizations included: phase analysis, chemical composition, metallography, microhardness, micro-scratch resistance and nano-indentation hardness. On wear testing, the counter body was a 30 mm diameter steel ball rotating at a tangential speed of 9.42 m/min and normal load of 0.54 N. The abrasive was a mono-crystalline diamond micro abrasive paste, 1 micrometer grit. Wear volumes were calculated by measuring the wear scars at various test intervals. In non-perforating tests, Archard's wear equation was directly employed for calculating coating wear rate as the slope of the linear least square data fit. In perforating tests, Allsopp's method was employed for the simultaneous determination of coating and substrate wear rates, from the slope and intercept values of the linear least square data fit. Coating specific wear rate values obtained from both non-perforating and perforating tests were very consistent, with a relative difference within 6%. Relative errors in specific wear rate values were estimated to be of the order of 0.05 for the coating and 0.2 for the substrate.

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“…The most commonly known and widely used technology of surface treatment which enables manufacturing of composite layers is combination of gas or plasma nitriding process with deposition of hard antiwear coatings via physical vapour deposition (PVD) methods-duplex technology [12][13][14][15]. The result of such configured technology is a possibility of production composite layer, consisting of nitrided layer and PVD coating formed directly on its surface.…”

Section: Introductionmentioning

confidence: 99%

Investigations of rheological properties of nitrided steels using thermodilatometric method with temperature modulation

Myśliński

Gilewicz

Olik

et al. 2016

J Therm Anal Calorim

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In this work were developed issues concerning the use of thermodilatometric methods for the evaluation of rheological properties of nitrided and non-nitrided steel substrates and systems composed of steel substrate and physical vapour deposition (PVD) coating. Analysis of the rheological properties of these systems (e.g. viscosity, ability to dissipate the energy of deformation or stress relaxation) is essential from the point of view of designing nitrided substrates to the so-called duplex processes: nitriding ? PVD, since the viscosity of the substrate affects the fracture toughness of the deposited coatings and their adhesion state. Analysed samples were made of 42CrMo4 steel and had shapes of a cylinder, and the nitrided layer consisted only of diffusion zone and had a thickness of 350 lm. The scope of research included analysis of the effect of thermal loads on rheological properties of the systems using created diagnostic curves (sequences of annealing at 290°C lasting for 26 h). Experimental measurements of elongation and temperature of the systems were made using thermodilatometric method with temperature modulation. In particular, were analysed the changes in the time shift between the temperature of the sample and its elongation s-corresponding to viscoelastic properties of the system. Was also determined the relationship between the changes of the introduced equivalent thermal expansion coefficient (corresponding to the thermomechanical interactions in the system) for the tested systems, and the stages of annealing cycles. Basing on obtained results, it was shown that the nitriding of steel substrates significantly enhances their thermal stability as compared to non-nitrided substrates. It was also shown that the nitrided substrate is less susceptible to heat-induced deformations. In addition, the used method enabled the identification of the influence of gas atmosphere in which annealing sequences were carried out, on rheological properties of substrates. In particular, for nitrided and non-nitrided substrates different discontinuity of changes in the a AC and s parameters as a function of annealing time at the moment of change the gas atmosphere from argon to air was observed.

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Duplex surface treatment of moulds for pressure casting of aluminium

Cited by 30 publications

References 21 publications

A strategy for the selection of multiple materials and processes fulfilling inherently incompatible functions: The case of successive surface treatments

A strategy for the selection of multiple materials and processes fulfilling inherently incompatible functions: The case of successive surface treatments

Micro-Scale Abrasive Wear Testing of CrN Duplex PVD Coating on Pre-Nitrided Tool Steel

Investigations of rheological properties of nitrided steels using thermodilatometric method with temperature modulation

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