Evaluation of interface adhesion of hot-dipped zinc coating on TRIP steel with tensile testing and finite element calculation

In this work, a methodology for the determination of the interface adhesion strength of zinc coating on TRIP steel is present. This method consists of a conventional tensile test in combination with finite element calculation. The relation between the average interface crack length and the applied tensile stress is determined on the partially delaminated coating with in-situ tensile test. The delamination process of zinc coating on steel substrate is simulated by using a two-grain finite element model with different interface adhesion strengths. By comparing the experimental observation with the finite element calculations, the interface adhesion strength is estimated. The interface adhesion strength of the zinc coating on transformation induced plasticity (TRIP) steel is found as high as 160 MPa. The influences of microstructural parameters of zinc coating including zinc grain orientation and grain size on the delamination behavior of the zinc coating are also analyzed with the finite element model

Internal stresses and microstructure of layer/substrate essemblies. Analysis of TiC and TiN coatings chemically vapour deposited on various substrated

Applied Science

Karakterisering van dunne titaancarbide lagen door middel van röntgendiffractie

Technische MateriaalwetenschappenApplied Science

Effect of Y Distribution on the Oxidation Kinetics of NiCoCrAlY Bond Coat Alloys

The relation between the Y distribution in the alloy and the growth kinetics of the developing oxide scale was studied for the thermal oxidation of two Ni–20Co–19Cr–24Al–0.2Y (at.%) alloys at 1,373 K: (i) a coarse-grain cast alloy with large Ni5Y intermetallic precipitates, and (ii) a fine-grain freestanding coating with small Ni5Y precipitates. Using a combination of experiments and model calculations, it is shown that the average growth kinetics of a NiCoCrAlY alloy are dependent on the size and distribution of Y-rich oxide inclusions (pegs) in the ?-Al2O3 oxide layer. Alumina scales containing a high density of small Y-oxide inclusions grow faster than ?-Al2O3 scales containing only a few, large Y-oxide inclusions. Upon oxidation of the freestanding coating, the Y-oxide inclusions in the scale attain their maximum size after the Y in the coating is completely consumed. After this point, a decrease in the average oxidation kinetics occurs.Surfaces & InterfacesMechanical, Maritime and Materials Engineerin

Work of adhesion of interfaces between M₂AlC (M = Ti, V, Cr) MAX phases and α-Al₂O₃

A fast and generic scheme is proposed to calculate the work of adhesion between two different materials or the cohesive energy between two crystal planes in a material. These calculations make use of the regular solution theory. This theory is extended to describe chemical interactions between atoms at either side of an interface. The so-called regular solution parameter is estimated from thermodynamic values tabulated or solution enthalpies obtained from a macroscopic atom model (MAM). Complex surface definitions at either side of an interface, both in composition and position of atoms, can be dealt with. The proposed scheme has been used to calculate the work of adhesion between M2AlC (M = Ti, V, Cr) type MAX phases and α-Al2O3. Next, the cohesive energy of the MAX-phases and alumina were determined. The cohesion of the M2AlC type MAX-phase is the weakest bond present in the M2AlC- α-Al2O3 systems.Accepted Author Manuscript(OLD) MSE-

Surface and Interface Research and Engineering Delft University of Technology: A Collection of Mini Posters

Delft University of Technolog

Modelling of surface segregation for palladium alloys in vacuum and gas environments

Surface segregation of a series of forty Palladium-based binary alloys has been investigated using a thermodynamic model based on an atom exchange approach. Their surface segregation behaviour, both in vacuum and in gas environments, were comprehensively estimated. The calculated results are in good agreement with the available experimental and computational data reported in literatures. Effects of mixing enthalpy, temperature, crystal orientation on the surface, elastic strain energy, adsorption and absorption of gases like H2, O2, CO have been discussed in detail. These results can be considered as basic guidelines to design novel Pd alloys for hydrogen separation membranes, sensors or catalysts. The model itself also offers a convenient and accurate routine to predict the surface segregation of other than Pd-based binary alloys in different gas atmospheres.(OLD) MSE-

A method for the experimental determination of surface photoemission core-level shifts for 3d transition metals

A method is presented to determine the photoelectron surface core-level shift (SCLS) of 3d transition metals using x-ray photoelectron spectroscopy. The experimental difficulties arising from the relatively large broadening of photoemission lines in the 3d transition series can be overcome by the analysis of the angular dependence of photoemission spectra. The proposed method has been demonstrated using well-defined single-crystal surfaces of copper. The observed values of the SCLS for copper are compared with those predicted by both ab initio calculations and a macroscopic atom model. The experimental determination of SCLSs opens alternative routes for collecting thermochemical data for surfaces/interfaces.Materials Science and EngineeringMechanical, Maritime and Materials Engineerin