The surfacing technologies are used for constitution of protection layer against wear and is destined for obtaining coating with high
hardness. Among many weldings methods currently used to obtain the hard surface layer one of the most effective way of hardfacing is
using flux cored arc welding. This additional material gives more possibilities to make expected hard surface layer.
Chemical composition, property and economic factors obtained in flux cored wire are much richer in comparison to these obtained with
other additional materials. This is the reason why flux cored wires give possibilities of application this kind of material for improving
surface in different sectors of industry.
In the present paper the imperfection in the layers was used for hardfacing process in different situations to show the possible application
in the surface layer. The work presents studies of imperfection of the welds, contains the picture of microstructures, macrostructures and
shows the results of checking by visual and penetrant testing methods.
The paper presents the analysis of temperature fields, phase transformations, strains and stresses in a cuboidal element made from S235 steel, surfaced with multipass GMA (Gas Metal Arc) method. The temperature field is described assuming a dualdistribution heat source model and summing up the temperature fields induced by the padded weld and by the electric arc. Dependence of stresses on strains is assumed on the basis of tensile curves of particular structures, taking into account the influence of temperature. The calculations were carried out on the example of five welds in the middle of the plate made of S235 steel. The simulation results are illustrated in graphs of thermal cycles, volume shares of structural components and stresses at the selected points of cross-section, and the temperature and strain distributions in the whole cross section.
We present a prototype of a simple, low-cost setup for a fast scatterometric surface texture measurements. We used a total integrated scatter method (TIS) with a semiconductor laser (λ = 638 nm) and a Si photodiode. Using our setup, we estimated the roughness parameters Rq for two reference surfaces (Al mirrors with flatness λ/10) and seven equal steel plates to compare. The setup is easily adaptable for a fast, preliminary manufacturing quality control. We show is possible to construct a low-cost measurement system with nanometric precision.
The thermochemical treatment applied to improve the surface properties of AZ91 consisted in heating the material in contact with AlSi10Mg powder at 445 oC for 30 min. During heat treatment process the powder was held under pressure to facilitate the diffusion of the alloying elements to the substrate and, accordingly, the formation of a modified layer. Two pressures, 1 MPa and 5 MPa, were tested. The resultant layers, containing hard Mg2Si and Mg17Al12 phases, were examined using an optical microscope and a scanning electron microscope equipped with an energy-dispersive X-ray spectrometer (EDS). The experimental data show that the layer microstructure was dependent on the pressure applied. A thicker, three-zone layer (about 200 μm) was obtained at 1 MPa. At the top, there were Mg2Si phase particles distributed over the Mg17Al12 intermetallic phase matrix. The next zone was a eutectic (Mg17Al12 and a solid solution of Al in Mg) with Mg2Si phase particles embedded in it. Finally, the area closest to the AZ91 substrate was a eutectic not including the Mg2Si phase particles. By contrast, the layer produced at a pressure of 5 MPa had lower thickness of approx. 150 μm and a two-zone structure. Mg2Si phase particles were present in both zones. In the upper zone, Mg2Si phase particles were regularly distributed over the Mg17Al12 intermetallic phase matrix. The lower zone, adjacent to the AZ91, was characterized by a higher volume fraction of Mg2Si phase particles distributed over the matrix composed mainly of Mg17Al12. The alloyed layers enriched with Al and Si had much higher hardness than the AZ91 substrate.
The article presents the results of research on the finishing of M63 Z4 brass by vibratory machining. Brass alloy was used for the research due to the common use of ammunition elements, cartridge case and good cold forming properties on the construction. Until now, the authors have not met with the results of research to determine the impact of abrasive pastes in container processing. It was found that the additive for container abrasive treatment of abrasive paste causes larger mass losses and faster surface smoothing effects. The treatment was carried out in two stages: in the first stage, the workpieces were deburred and then polished. Considerations were given to the impact of mass of workpieces, machining time and its type on mass loss and changes in the geometric structure of the surface. The surface roughness of machining samples was measured with the Talysurf CCI Lite optical profiler. The suggestions for future research may be to carry out tests using abrasive pastes with a larger granulation of abrasive grains, and to carry out tests for longer processing times and to determine the time after which the parameters of SGP change is unnoticeable.
The influence of the processing temperature of polylactide (PLA) on the structure geometry changing (SGC) and its functional properties were analyzed. The PLA samples subjected to testing were manufactured using incremental fused deposition modeling technology (FDM) with processing temperatures ranging from 180°C to 230°C. The topography of the PLA surfaces formed during heat dissipation and generated by the work table was analyzed. The roughness measurements were carried out using the profile method in accordance with PN ISO 3274: 2011. Registered profiles of the surfaces were analyzed numerically in fractal terms using the method of the S(Δx) structure function. The functional properties of the PLA surface were evaluated on the basis of Abbott-Firestone curves, according to PN EN ISO 13565–2: 1999.
In the summer of 1979, in South Spitsbergen investigations of the extreme temperatures of the ground surface were carried out. The investigations permitted the determination of the magnitude of the extreme temperatures of the ground surface and their relation to the air temperature. The spatial variability of the extreme temperatures of the ground surface was observed.
When conducting geodetic and gravimetric measurements, there is a problem of projecting them to the reference surface. Since the gravitational field is inhomogeneous under the real conditions, the problem arises of determining the corrections to the measured values of gravitational acceleration in order to use the obtained data for the subsequent solutions of projection problems. Currently, the solution to this problem is performed using a Bouguer reduction, which requires information about the internal structure of the upper layer of the earth’s surface, topography, etc. The purpose of this study is to develop a methodological approach that would allow to determine the reduction (projection) corrections for gravitational acceleration on technogenic and geodynamic polygons without using data about the distribution of surface layer density and topography. The research process is based on the use of mathematical analysis methods and a wide range of experimental geodetic and gravimetric measurements. In the course of the performed researches, an algorithm was obtained and a practical implementation of the determination of the corrections in the measured values of gravitational acceleration on the basis of geodetic and gravimetric measurements was carried out at the certain geodynamic polygon in order to bring all corrections to one level surface.
The article presents research on solid particle erosive wear resistance of ductile cast iron after laser surface melting. This surface treatment technology enables improvement of wear resistance of ductile cast iron surface. For the test ductile cast iron EN GJS-350-22 surface was processed by high power diode laser HPDL Rofin Sinar DL020. For the research single pass and multi pass laser melted surface layers were made. The macrostructure and microstructure of multi pass surface layers were analysed. The Vickers microhardness tests were proceeded for single pass and multi pass surface layers. The solid particle erosive test according to standard ASTM G76 – 04 with 30°, 60° and 90° impact angle was made for each multi pass surface layer. As a reference material in erosive test, base material EN GJS-350-22 was used. After the erosive test, worn surfaces observations were carried out on the Scanning Electron Microscope. Laser surface melting process of tested ductile cast iron resulted in maximum 3.7 times hardness increase caused by microstructure change. This caused the increase of erosive resistance in comparison to the base material.