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Influence of surfactants in electroless nickel bath on properties of Ni-P coatings on AZ91 magnesium alloy
Buday, Patrik ; Wasserbauer, Jaromír (referee) ; Buchtík, Martin (advisor)
This bachelor thesis deals with the effect of surfactants on mechanical properties and structure of Ni-P coatings on AZ91 magnesium alloy. The theoretical part of the thesis includes summary of basic knowledge about magnesium alloys, surfactants and electroless deposition of Ni-P coatings, including a detailed description of Ni-P reduction on substrate. The theoretical part is concluded by current research in the field of Ni-P coatings. In the experimental part, morphology of Ni-P coatings was observed by electron microscopy (SEM). Using a light microscope (LM), the effect of surfactants on the deposition rate was observed. By means of energy dispersion analysis, the average phosphorus content of Ni-P coatings was determined. The hardness as a mechanical property of these coatings was determined using a micro hardener.
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Characterization of corrosion resistance of nickel-phosphorus coatings on magnesium alloys
Kotland, Vojtěch ; Březina, Matěj (referee) ; Wasserbauer, Jaromír (advisor)
This master’s thesis is focused on corrosion resistance of nickel-phosphorus coatings on magnesium alloy AZ91. In the theoretical part is summarized current knowledge about magnesium alloys and electroless deposition of Ni-P coatings including ongoing reactions. Theoretical part also lists all substances contained in the nickel bath and their specific use there. In the second half of theoretical part are discussed corrosion and immersion tests. Theoretical part is ended by review aimed towards the research in areas of immersion tests. Experimental part describes individual steps of pretreatment on magnesium alloy and then deposition of the Ni-P coating. Composition and morphology of deposited Ni-P coating and magnesium alloy were studied using energy dispersive spectroscopy. Experiment part also contains list of experiments trying to figure out ideal thickness of low-phosphorus coating which is able to protect magnesium alloy from corrosion. Master’s thesis is ended with the list of immersion tests and results which outcomes from them.
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Nickel coatings and their properties
Buchtík, Martin ; Tkacz, Jakub (referee) ; Zmrzlý, Martin (advisor)
The aim of the bachelor’s thesis was summary of existing knowledge concerning to electroless deposition of nickel coatings and their properties. In the theoretical part there are two chapters. In the first chapter present knowledge of chemical nickel plating is described in details. It also discuss mechanisms of this type of coating and individual components of nickel plating bath. In the second chapter there is summarized knowledge of composite coatings deposition and description of their mechanical properties. The experimental part deals with deposition of composite coatings on steel substrates and heat treatment of Ni-P coatings. Dependence of microhardness on temperature of heat treatment was studied and then there is also described dependence of microhardness on duration of heat treatment. Deposited coatings, their morphology and composition were studied using scanning electron microscope and EDS analysis. The values of microhardness of both types of coatings were measured and compared using microhardness tester.
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Fabrication of conducting patterns by material electroless plating of printed precursor
Kováčová, Silvia ; Gemeiner,, Pavol (referee) ; Dzik, Petr (advisor)
The subject of this diploma thesis is the preparation of conductive structures by electroless plating of an extruded precursor. The experimental part deals with the preparation of standard patterns based on the length of immersion time in a coppering bath. The precursor layers were applied with Fujifilm Dimatix to various receiver substrates. The individual substrates with the precursor layer were immersed in the copper solution within different time intervals. The structure of the layers of grown copper and their thickness was characterized by a profilometer.
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Study of the microstructure of deposited Ni-P coatings with different phosphorus contents
Najser, Tomáš ; Kosár, Petr (referee) ; Wasserbauer, Jaromír (advisor)
The aim of this bachelor thesis was the preparation and characterization of Ni-P coatings with different phosphorus contents on the substrate of AZ91 magnesium alloy. The theoretical part deals with magnesium alloys and specifies the utilized substrate AZ91. It also focuses on Ni-P coatings, their microstructure and their properties. However, there are also described factors affecting the rate of deposition and the resulting behavior of these coatings. Last but not least, the theoretical part summarizes the basic principles of laboratory methods used in the experimental part for observation and characterization of samples. Conclusion of the theoretical part consists of several background researches where the authors deal with similar problems and factors influencing the resulting behavior of Ni-P coatings. The experimental part is focused on the deposition of each Ni-P coatings on the AZ91 alloy and their characterization. The study of deposited Ni-P layers was focused on the determination of their microstructural texture by XRD method, mechanical properties and elemental composition depending on phosphorus content.
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Heat hardening of Ni-P based coatings prepared on wrought magnesium alloys
Kotland, Vojtěch ; Březina, Matěj (referee) ; Wasserbauer, Jaromír (advisor)
This bachelor’s thesis is focused to hardening of nickel-phosphorus coatings on magnesium alloys. In the theoretical part are listed current knowledge about magnesium alloys and electroless deposition of Ni-P coatings for which is also stated mechanism and function of components contained in the bath. Theoretical part is ended by review aimed to the research in areas of chemical coating. Experimental part describes individual steps of pretreatment on magnesium alloy AZ31 and then planting of Ni-P coating on thus prepared alloy. In the next part is stated range of used hardening temperatures and mechanical repercussion to that. Composition and morphology of deposited coating and magnesium alloy were studied using scanning electron microscopy.
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Galvanic plating of magnesium alloy with Ni-P bond coat
Zahálka, Martin ; Kosár, Petr (referee) ; Wasserbauer, Jaromír (advisor)
Cílem této diplomové práce jse najít nejnižší možnou tloušťku nikl-fosforového povlaku, který může být galvanicky pokoven mědí bez defektů na horčíkové slitině, nikl-fosforového nebo měděného povlaku. V teoretické části jsou shrnuty poznatky o hořčíkových slitinách a jejich korozi. Navíc se teoreticá část zaměřuje na popis procesu bezproudého niklování a elektrochemického pokovování mědí a jejich porovnání. Na konci teoretické části je shrnut současný výzkum o elektrochemickém pokovování hořčíkových slitin. V experimentální části byl popsán proces přípravy povlaků Ni-P a Cu na horčíkové slitině AZ91. Na jedné vrstvě a dvojité vrstvě Ni-P povlaku byla provedena elektrodepozice mědi. Navíc byl diskutován vliv předůpravy před samotnou elektrodepozicí mědi. Za účelem zjištění korozních vlastností vzorků byl vykonán potenciodynamický test. Následně byly připraveny metalografické výbrusy jednotlivých vzorků a pomocí světelného a rastrovacího elektronového mikroskopu byla provedena charakterizace. Na konec bylo zjištěno prvkové složení jednotlivých povlaků pomocí EDX analýzy.
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Ni-P based coatings preparation on AZ61 wrought magnesium alloy after heat treatment
Otoupal, Dominik ; Tkacz, Jakub (referee) ; Kosár, Petr (advisor)
The aim of the bachelor’s thesis is preparation of heat treated wrought magnesium alloy AZ61 and exclusion nickel-phosphorus coating using electroless deposition to the original and heat treated magnesium alloy AZ61. The theoretical part contains two main chapters. The first chapter describes the alloy AZ61. The second part deals with electroless deposition of nickel-phosphorus coating. At the conclusion of the theoretical part is searches on the topic. Experimental part deals with characterization and description of the magnesium alloy, its heat treatment and electroless plating. They were studied chemical and mechanical properties of the original and heat treated AZ61 and nickel-phosphor coating. For the study methods of scanning electron microscopy with energy-dispersive spectroscopy, optical light microscope and Vickers’s microhardness was used.
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Complete characterization and comparison of lacquer / Ni-P / AZ91 and lacquer / AZ91 systems
Šomanová, Pavlína ; Doskočil, Leoš (referee) ; Buchtík, Martin (advisor)
The aim of this bachelor thesis was to compare the influence of Ni-P coating and varnish on the corrosion properties and chemical – physical properties (adhesion) of the magnesium alloy AZ91. The theoretical part contains the information about the alloy AZ91 itself and its microstructure, following by discussion about Ni-P coating, its properties, the process of the electroless deposition and composition it the nickel bath. Next chapter focuses on information about varnishes, its function and the process of its application on the surface of the substrate. Theoretical part closes with the summary of current research in the field of Ni-P coatings applied on magnesium alloys. The experimental part focuses on analysis of the microstructure of AZ91 alloy. The microstructure of the Ni-P coating and of the system Mg alloy/Ni-P coating/varnish was 4 examined by scanning electron microscope (SEM) and inverted microscope. During the next phase was thickness and hardness measured and composition measured by EDS analysis. The factor of the heat treatment of the samples and its impact on the final microstructure, hardness and corrosion resistance was taken in account. Finally, several samples were modified with the layer of the varnish and its thickness and the influence on the corrosion resistance ware measured. Samples were tested with electromechanical impedance spectroscopy (EIS), the corossion resistance were tested by neutral salt spray (NSS) and adhesive test was performed. The results showed, that Ni-P coating and the layer of varnish had positive impact on the corrosion resistance and the hardness of AZ91. The corrosion resistance of the samples modified with heat treatment was much lower, because of the contracting, which causes creation of the cracks. Also, the layer of varnish had positive effect on anticorrosion properties of tested AZ91 alloy.
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Fabrication of conducting patterns by material electroless plating of printed precursor
Kováčová, Silvia ; Gemeiner,, Pavol (referee) ; Dzik, Petr (advisor)
The subject of this diploma thesis is the preparation of conductive structures by electroless plating of an extruded precursor. The experimental part deals with the preparation of standard patterns based on the length of immersion time in a coppering bath. The precursor layers were applied with Fujifilm Dimatix to various receiver substrates. The individual substrates with the precursor layer were immersed in the copper solution within different time intervals. The structure of the layers of grown copper and their thickness was characterized by a profilometer.
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