International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The paper discusses the possibilities of joining thin-walled metals and composites reinforced with bidirectional carbon/glass fibres. The experimental part of the paper contains metallographic sections and results of load-bearing capacity testing of pilot metalcomposite joints with thermoplastic matrix and glass and carbon fiber reinforcement, formed by thermal drilling technology. As a result, a sequential joining method is proposed which can achieve the optimum joint geometry with a hem to keep the joint from opening under tensile stress.

The contribution is focused on the analysis of the surface roughness after applying the conversion layer using phosphating. In the experiment, uncoated deep-drawn steel DC 04 was used as the base material. During the application of the conversion layer, changes in surface roughness were studied with respect to the phosphating time, which was 3, 5 and 10 minutes. The achieved results provide information for other technological operations such as creating joints by gluing, where the correct anchoring of the glue is important for sufficient adhesion to the surface.

In the contribution, the surface quality of the steel substrate is analyzed from the point of view of its microgeometry as a set of quantities capturing the differences of individual surface changes. The subject of investigation are the surfaces of steel substrates, i.e. the base material, degreased surface, standard galvanized surface, surface after galvanizing and subsequent chromating, surface after phosphating and surface after phosphating and application of RAL coating.

The contribution is focused on the analysis of the roughness of metal surfaces after applying a conversion layer using phosphating. The types of basic materials is used in the experiment hot-dip galvanized microalloyed steel HX340LAD+Z. During the application of the conversion layer, changes in surface roughness were studied with respect to the phosphating time, which was 3, 5 and 10 minutes. The paper deals with the evaluation of the relationship between the individual roughnesses parameters of pre-treated surfaces using correlation analysis. Based on the measured roughness values on the surfaces, the standard of statistical significance of the correlation between the observed parameters was determined from them. The achieved results provide information for other technological operations such as the creation of adhesive joints, where the correct anchoring of the adhesive is important for load bearing capacity of joints.

The article is focused on the study of the integrity of the material that is used in the automotive industry in process of creating joints by combined technology. The article describes the study of the properties of chemically pretreated surfaces by phosphating technology. When creating new surfaces by phosphating, a new type of phosphate layer was used using modern conductive compounds of polyaniline salts. The pretreated surfaces were investigated in terms of structure, 2D and 3D microgeometry, contact angle in relation to the determination of surface wettability and surface energy. The experiment was realized in order to identify the connections between individual factors of the process and roughness characteristics.

Currently, one of the most important and monitored surface properties is the ability to achieve the highest possible level of adhesion after applying a layer of paint or glue. To guarantee this property, it is extremely important to choose the right surface pretreatment. The paper is focused on chemical surface pretreatment and subsequent evaluation of morphological surface changes after application of various selected types of chemical pretreatment based on roughness parameters.

The main goal of this contribution is study the microgeometry of blasted surfaces. The aim is to design suitable microgeometric characteristics for the description of pretreated surfaces, experimentally verify the influence of blasting agents of various shapes and sizes on the microgeometry of metal surfaces. The following types of evaluation are used to meet this goal: 2D roughness determinat ion and profilograms, 3D surface visualization and surface volume determination. The results of the experimental part will contribute to the optimization of technological parameters of the tearing process.

Surface quality and its evaluation is currently a very important part of surface preparation for all types of technologies involved in surface formation. Knowledge of the new surface formation mechanism is of great importance from the point of view of production, because it allows to understand the nature and properties of the newly created surface and thus gives the opportunity to both improve the processes used and create a smooth process. surfaces. Therefore, any changes that occur in the surface layer of the component can be considered as changes in the surface quality. The paper deals with the expansion of current knowledge in the evaluation of metal surfaces microgeometry in terms of current trends.

The paper provides an overview of the load-bearing capacity of joints of the same and unequal thin steel sheets formed on different pretreated surfaces by adhesive bonding. Four types of surface preparation and rubber-based adhesive were tested. The joints were subjected to a climatic test according to VW: PV1200. The change in the load-bearing capacity of the joints was evaluated on the basis of the force at the joint failure, the type of failure and on the basis of the load to displacement ratio.

The paper is focused on research results of dissimilar materials joining by adhesive bonding. Galvanized and non-galvanized steel sheets with a thickness of 0.8 mm were joined together. To compare the effect of the presence or absence of the Zn layer on the strength of the adhesive joints, control joints were made, consisting only of galvanized and only of non-galvanized materials. The materials were joined on one hand without any surface preparation, and on the other hand prepared by degreasing and mechanical roughening with sandpaper. Epoxy/PVC-Polymerblend adhesive with glass beads was used for bonding to check the thickness of the adhesive. The tensile lap-shear strength was tested according to DIN EN 1465. The joints made of galvanized materials only proved the highest, the joints made of nongalvanized materials only proved the lowest shear strength. The mixed joints did not reach the joint strength of galvanized materials, but exceeded the joint strength of non-galvanized materials. The adhesion of the adhesive to non-galvanized substrates seems to be the limiting factor of the strength of mixed joints

The quality of the resulting surface treatment is influenced especially by the pre-treatment of the substrate, the design of the surface treatment such as the choice of the coating system, the method and the quality of application. From a variety of chemical surface pre-treatment methods, Bonderite chemical pre-treatment is at the forefront. This chemical pre-treatment is used at ambient temperature, phosphate-free. It forms a nano-ceramic protective layer on steel, zinc and aluminum surfaces. The use of Bonderite gives the coating a high quality, which shows good adhesion and excellent corrosion protection. Contribution is devoted to the evaluation of these properties

The article is focused on the research of the influence of different blasting means on the surface of the titanium alloy Ti6Al4V, which was made by the sintering technology of layered metal powders (DMLS) in terms of microgeometry. The resulting microgeometry values of the titanium alloy placed on the platform in different sectors. Individual sectors had different laser power settings. The blasting was carried out at a constant pressure of 6 bar. Samples were then subjected to roughness measurement by contact method in accordance with STN EN ISO 4287. Individual parameters were subsequently statistically evaluated. A 3D topography of roughness of individual blasted materials was made.