The output of this diploma work (dissertation) will be design of a construction for a tester enabling simulation of riding a vehicle with mounted snow chain in winter season on road without snow. The result of testing will be abrasion of single link of the chain caused interaction with surface of road and strength test of weld link e.g. when is pass gravelly surface.

In the business of packaging engineering, a large consumption of time is placed on evaluating new materials to provide cost savings to a company. This evaluation is made by using test methods such as those found in ASTM D4169-16, which helps to simulate shipping and distribution conditions. A key problem is that this test method can take up to multiple months, and sometimes years to complete. The apparatus created in this study allows for a comparison to be made between currently used films and prospective films in approximately ten hours. This allows for a prescreening of new films to be done before completing full ASTM shipment and distribution testing.This study focuses on coextruded multilayer polymer films and the damage brought upon them in forms of puncture and abrasion through shipment and distribution.

The marine environment is polluted by plastics of all forms and sizes. To reduce this serious pollution, it is important to identify its sources. This work focuses on the me-chanically induced breakdown of plastic into smaller fragments as a source of secondary microplastic, the time scale in which these microplastics are formed as well as the influ-ence of different environmental conditions like matrix conditions, collision potential or UV irradiation on the abrasion and fragmentation behaviour of plastic debris. Since a systematic investigation of parameter influence is not possible in the environ-ment, laboratory experiments were developed to simulate natural conditions such as drift on the beach or wave action in the (low tide) surf and swash zone. For this purpose, selected plastic objects (PET bottles, HDPE caps, PS cups and LDPE bags) were ex-posed to collision and/or friction forces under different conditions. Besides visual in-spection of the destruction procedure, a number of different methods was used to char-acterize the process, e.g., counting of visible fragments (larger than 350 μm), micro-scopic analysis of the surface structure (binocular, SEM) and highly resolved analysis of particle numbers in the size range below 350 μm. In order to extract microplastic parti-cles (<5 mm) from the matrix, extraction methods were developed that were adapted to the given sample properties (matrix volume). Furthermore, based on the particle num-bers, the power law model was applied to analyse the fragmentation process in the con-text of the observed particle size distributions. Plastic samples exhibited various signs of mechanical impairment in form of surface abrasion, cracks, tears, perforation, crumpling and finally fragmentation. The formation of fragments in different sizes (macro-, meso- and microplastics) was observed. The plastic objects were classified according to their degree of destruction to elucidate the effect of the different experimental conditions. Results show that fragmentation and abrasion depend on individual properties of the plastic objects such as thickness or shape and on the potential of weakening the plastic structure by mechanical forces (collisions) or chemical degradation (UV irradiation). Environmental conditions also influence the plastic damage; surface abrasion plays a major role on the beach; fragmentation will most likely happen in the surf- and in the swash zone. However, both processes occur simultaneously and interact with each oth-er. Formation of secondary microplastics was shown to be likely in the marine environ-ment; it must therefore be considered as an important process in the light of microplastic contamination.

The adhesive mechanism is one of the most significant degradation processes of the edge in metal cutting. Although knowledge about adhesion and edge buildup (BUE) has increased in recent years, there are still areas that are less explored. The adhesion has a regularity in the form of clusters: In a cluster, the chips vibrates with a certain frequency. The frequency varies with several influencing factors. In this thesis, a possible connection between acoustic signals and wear of the cutting edge is researched. Audio signals from cutting edges with varied wear must be analyzed. To investigate the adhesive mechanism, the machining process turning will be used. The cutting edge is analyzed optically with a microscope. According to previous research, the adhesive wear has been shown to be mostly dependent on the cutting speed. The size of the stagnation zone depends largely on the friction angle and the shear plane angle, where the friction angle changes depending on the rake angle and the shear plane angle changes depending on the cutting speed. Adhesion wear has been shown to be a fatigue process. This thesis aims to investigate the development of the adhesive mechanism towards the wear status of the tool. The end goal is to construct a model that explains what happens in the wear zones on the edge and to detect changes in the acoustic signal from the cutting zone that occurs during adhesion wear. The cutting zone sound from two cutting tools with different cutting times is used in Fourier analysis. Insert number two will be worked until chipping occurs and examined optically with a microscope between each cycle to verify if chipping was present. One chip was examined after each cycle under a microscope to see if residues from the insert got stuck on the chips. Cycle number one with insert number one (new edge) shows no clear adhesive mechanism while cycle number one with insert number two shows a clear adhesive mechanism. The same cutting speed is achieved during cycle number five and number 18 with cutting tool number two. The frequency increases 11% and the amplitude decreases 42% from cycle number 5 to cycle number 18. Chipping occurred in cutting tool number two after 25 cycles. The frequency of the adhesive mechanism increases, and the amplitude decreases when the insert wears. A reasonable hypothesis is that the surface that is welded together becomes larger with increased wear: The spring in the adhesive system becomes stronger while the mass remains constant. A hypothesis that the amplitude of the adhesive mechanism is low during cycle number one with insert number one may be due to the fact that the workpiece used was at room temperature. No significant degeneration has occurred of the chip surface.

The diploma thesis assesses the current state of the Hulín gravel and sand plant and pays attention to abrasions of severely damaged banks of the reservoir. With the help of the design of a suitable biotechnical stabilization, the receding of the shoreline in the section of interest will be prevented. The basis for the processing of appropriate bank stabilization proposals is the results achieved using a method of determining shore retreat. The individual developed variants of the bank remediation solution emphasize the use of vegetation support, especially suitable bank stands to ensure the stability of the banks and protection against abrasion.

The Ph.D. thesis is focused on a surface degradation mechanisms under combined heat and mechanical load. The objects of examination are work rolls from hot rolling mill which suffer such a load. In first chapter, the hot rolling process, the design, the manufacturing process and present materials of work rolls are described. The state-of-the-art study of work roll surface degradation mechanisms – wear, oxidation, thermal and contact fatigue are described in the second chapter. The characterization, the formation, the mechanisms of progression and the effects of each surface degradation mechanism is described step by step. The state-of-the-art study of analytical and numerical models which are related to hot rolling process is described in third chapter together with their limitations and flaws. The next chapters contain design of an analytical, an optimized macroscopic and a microscopic model for study of the work roll stress state. The macroscopic and the microscopic model is based on finite element method and they are implemented in ANSYS Programming Design Language. The models are used to process several case study which are based on previous experimental work of the Heat transfer and fluid flow laboratory. The results from case studies specify and expand the knowledge of work roll stress state. The results show the portion of each loading factor on the whole stress state. In addition, time and depth depended distribution of stress state is presented. The results from macrosferic model illustrate the cause of spalling and a rupture of the work roll. The results from the microsferic model show the cause of creation of the to-surface-parallel cracks within carbides of high chromium irons. Last chapter summarized of all results gathered from case studies together with the goals for further research definition. The necessary steps for further cognition are stated. The thesis contains a large set of appendixes with deeper discussion of several related topics. These appendixes represent the one third of whole the thesis.

Aitik is a large copper porphyry type deposit located in northern Sweden, currently exploited at an annual rate of approximately 45Mt. The ore's exceptionally low head grade of 0.22 % Cu and varying degrees of hardness across the entire deposit pose challenges to the two fully autogenous grinding lines, each of which comprises a 22.5 MW primary autogenous mill in series with a pebble mill. The variability in ore grindability frequently leads to fluctuations in mill throughput.  Within the framework of a geometallurgical approach, the present study investigated the relationships between ore grindability and modal mineralogy. For this purpose, drill core samples from different lithologies were subjected to Boliden AB's in-house grindability tests. This laboratory-scale autogenous grinding test generates a grindability index Ks mainly related to abrasion breakage, which is a significant breakage mechanism within autogenous mills. The test results suggested divergent degrees of grindability within and across the selected rock types. Furthermore, subsequent sieve analyses identified a relationship between the grindability index, PSD, and the proportions of fines generated by abrasive grinding. A combination of scanning electron microscopy, X-ray powder diffraction, and X-ray fluorescence analyses was performed for the grinding products and bulk mineral samples. The resulting mineralogical and elemental properties were correlated to the parameters from the grindability tests. It was shown that the main mineral phases, such as plagioclase, quartz, and micas, correlate well with the grindability indices. Similar correlations were found regarding the sample's chemical composition, attributable to the main mineral phases. Derived from the previous findings, two exemplary linear empirical models for the calculation of grindability based on either mineral contents or chemical composition were presented. Careful examination of the mineralogical data revealed that the prevalent abrasion breakage mechanism leads to constant and continuous removal of mineral particles from the sample's surface. No indications for a preferential abrasion of any mineral phases were found.  A further inverse correlation between the sample's calculated average weighted Mohs hardness based on modal mineralogy and the grindability index Ks was established. Hence, it was proposed that a higher Mohs hardness results in a finer grinding product, oppositional to the Ks-values. Since Ks can be interpreted as a measure of abrasiveness, it can be stated that abrasiveness decreases with an increasing average sample hardness and vice versa.  Moreover, mineral liberation information provided by scanning electron microscopy was associated with the parameters mentioned earlier. It was determined that different degrees of mineral liberation were reached within specific particle size classes. The identified relationships between grindability, modal mineralogy, and element grades may help Boliden develop a predictive throughput model for Aitik to be integrated into the mine's block model. Based on this information, a strategy for smart blending could be developed, where run of mine material from ore blocks of varying grindabilities could be blended to attain the target plant throughput.

Pollution of air represents the contamination with matter that can affect both humanhealth and the environment. Road dust has been recognized as a dominant source ofparticulate matter and one of the factors that contributes to its development is the useof gritting sand. Gritting sand is being used during snowy winter conditions as atraction control method. During spring season, when snow and ice melt and surfacesdry out, and the influence of traffic, asphalt surface wear, particle ejection from tires,etc; under the effect of their interaction, cause the formation of particulate matter.A general aim of this study was to perform analysis of factors which can be consideredresponsible generating road pollution, with resistance to abrasion of gritting sandbeing a potential key problem. The correlation between the use of studded tires andparticulate matter formation has been considered to be one of major issues in urbanareas.In order to carry out this investigation, an individual study case was considered,measurements indicated that levels of pollution increased even after studded tires werebanned.The literature review revealed important knowledge gaps regarding the quantificationof particulate emissions from non-exhaust sources, most importantly, emissions due tolow quality gritting sanding. At this point, very little information is available thatcould be used for determining the resistance to abrasion of gritting sanding material.This is further supported by numerous institutions and companies, all suggesting thatquality of gritting sand is not taken into consideration. Gritting sand is part of abigger problem which also involves types of pavement, types of tires, weather,background pollution, etc. Furthermore, there is no practical method to characterizewear of resistance of gritting sand.

This work is made up of three parts. Part one looks to establish design values for two types of three ply access mats from the U.S. South and Midwest. The mats were subject to 3 point bending tests to determine strength and stiffness values. Values for MOE (Modulus of Elasticity) and MOR (Modulus of Rupture) are reported by region and mat design. Part two tested five species groups of hardwoods for wear resistance and hardness. These species groups include white oak, red oak, ash, sweetgum and hickory. These tests for wear were performed on a Navy-Type Wear Tester according to ASTM D2394-17. Hardness specimens were tested with the Janka method according to ASTM D143-14. The third and final part looks at the impact of thermomechanical densification on rate of wear in five species groups of hardwood. The species groups were white oak, red oak, ash, sweetgum and hickory. Samples were pressed at 1000psi at temperature of 350 degrees Fahrenheit, in order to plasticize the wood and densify it at the same time. These samples were then tested on the Navy-Type Wear Tester to determine whether densification had an impact on wear resistance.

Inorganic-organic hybrid materials have been developed using sol-gel reactions of a trialkoxysilylated organic compound and a metal or semi-metal alkoxide and applied as coatings on polymeric or metallic substrates. Many of these coatings have demonstrated good to excellent abrasion resistance. Abrasion resistant coatings were prepared by hydrolysis and condensation of mixtures of a triethoxysilylated diethylenetriamine (f-DETA), tetramethoxysilane (TMOS), water and an alcohol in the presence of an acid catalyst (a one-step hydrolysis approach). The influences of many formulation and processing variables on the gelation time, optical properties, hardness and abrasion resistance were investigated. An aminolysis mechanism was also proposed to explain the adhesion between sol-gel derived coatings and polycarbonate substrates promoted by a 3-aminopropyltriethoxysilane (3-APS) primer. FT-IR, GPC, 1H and 13C NMR, XPS experiments were conducted to support this mechanism. The f-DETA/TMOS system is essentially a binary system of an alkyltriethoxysilane (T) and a tetraalkoxysilane (Q). At pH 0-2 and pH 4-5, the relative condensation reactivities of the T and Q species in this system were compared using 29Si NMR spectroscopy. After thermal curing, 13C or 29Si solid state NMR spectroscopy was used to estimate the extent of hydrolysis of the urea linkages in f-DETA, the concentration of residual alkoxysilane groups, and the extent of condensation for both T and Q species. The dependence of the morphology of f-DETA/TMOS gels on the pH and the water concentration was also investigated using AFM, SEM and SAXS. Many other trialkoxysilylated organic compounds containing urea, urethane, epoxy and siloxane linkages were also synthesized and utilized to prepare abrasion resistant coatings via a one-step hydrolysis approach, a two-step hydrolysis approach or a moisture-curing approach. Coatings derived from many of these systems or approaches demonstrated abrasion resistance comparable to that of the f-DETA/TMOS coating. Thin coatings were also derived from cubic octasilicate monomers via hydrosilylation or sol-gel reactions. These coatings were very transparent but unfortunately lacked abrasion resistance. / Ph. D.