Příprava a charakterizace Ni-P povlaku na lité hořčíkové slitině AZ91
Loading...
Date
Authors
ORCID
Advisor
Referee
Mark
A
Journal Title
Journal ISSN
Volume Title
Publisher
Vysoké učení technické v Brně. Fakulta chemická
Abstract
Táto bakalárska práca sa zaoberá bezprúdovou depozíciou nikel-fosforovej (Ni-P) vrstvy na horčíkovej zliatine AZ91. V úvode teoretickej časti sú zhrnuté základné poznatky o zliatinách horčíku so zameraním na zliatinu AZ91, vplyve použitých legujúcich prvkov a nečistôt a o jej mikroštruktúre. Teoretická časť pokračuje pojednaním o Ni-P povlaku so zameraním na zloženie kúpeľa, vplyve a účinku jeho jednotlivých zložiek. Ďalej sa v tejto časti nachádza porovnanie s galvanickým niklovaním. Na záver teoretickej časti bol zhrnutý súčasný výskum použitia bezprúdovej depozície Ni-P vrstvy na horčíkovej zliatine AZ91. V praktickej časti bol pripravený Ni-P povlak na horčíkovej zliatine AZ91, pozorovaná mikroštruktúra horčíkovej zliatiny a Ni-P vrstvy, zmeraná rýchlosť depozície, hrúbka, mikrotvrdosť a zloženie povlaku. Taktiež bol pozorovaný vplyv jeho tepelného vytvrdenia. Zistilo sa, že je možné pripraviť kvalitný Ni-P povlak na horčíkovej zliatine AZ91, ktorý bol bez viditeľných defektov, alebo zjavných nežiadúcich medzivrstiev, avšak tepelným vytvrdením povlaku dochádza k jeho praskaniu. Na stanovenie koróznej odolnosti bolo vykonané potenciodynamické meranie, výsledkom ktorého bolo zistenie, že nevytvrdený Ni-P povlak predstavuje vhodnú protikoróznu ochranu. Avšak tepelným vytvrdením sa korózna odolnosť vplyvom popraskania povrchu zhoršila až na úroveň čistej zliatiny AZ91.
This bachelor thesis deals with electroless deposition of nickel-phosphoric (Ni-P) coating on AZ91 magnesium alloy. At the beginning of the theoretical part, there is a summary of basic knowledge about magnesium alloys with focus on AZ91 alloy and the influence of alloying elements and impurities and its microstructure. The theoretical part continues with the discussion of the Ni-P coating, focusing on the composition of the bath, the influence and the effect of its individual components. Next, there is a comparison with galvanic nickeling. At the end of the theoretical part, the current research of the use of electroless deposition of Ni-P layer on AZ91 magnesium alloy is summarized. In the practical part, there is the preparation of the Ni-P coating on the AZ91 magnesium alloy, the observation the microstructure of the magnesium alloy and the Ni-P layer, and rate of deposition, the thickness, the microhardness and the composition of the coating was measured. The effect of its heat treatment was also observed. It has been found that it is possible to produce a high-quality Ni-P coating on an AZ91 magnesium alloy which has no visible defects or obvious undesirable interlayers, however the heat treatment of the coating causes its cracking. To determine the corrosion resistance, a potentiodynamic measurement was performed, resulting in the finding that the Ni-P coating without heat treatment was a suitable corrosion protection. However, after heat treatment, the corrosion resistance due to cracking of the surface deteriorated to a level of bare AZ91 alloy.
This bachelor thesis deals with electroless deposition of nickel-phosphoric (Ni-P) coating on AZ91 magnesium alloy. At the beginning of the theoretical part, there is a summary of basic knowledge about magnesium alloys with focus on AZ91 alloy and the influence of alloying elements and impurities and its microstructure. The theoretical part continues with the discussion of the Ni-P coating, focusing on the composition of the bath, the influence and the effect of its individual components. Next, there is a comparison with galvanic nickeling. At the end of the theoretical part, the current research of the use of electroless deposition of Ni-P layer on AZ91 magnesium alloy is summarized. In the practical part, there is the preparation of the Ni-P coating on the AZ91 magnesium alloy, the observation the microstructure of the magnesium alloy and the Ni-P layer, and rate of deposition, the thickness, the microhardness and the composition of the coating was measured. The effect of its heat treatment was also observed. It has been found that it is possible to produce a high-quality Ni-P coating on an AZ91 magnesium alloy which has no visible defects or obvious undesirable interlayers, however the heat treatment of the coating causes its cracking. To determine the corrosion resistance, a potentiodynamic measurement was performed, resulting in the finding that the Ni-P coating without heat treatment was a suitable corrosion protection. However, after heat treatment, the corrosion resistance due to cracking of the surface deteriorated to a level of bare AZ91 alloy.
Description
Citation
BRESCHER, R. Příprava a charakterizace Ni-P povlaku na lité hořčíkové slitině AZ91 [online]. Brno: Vysoké učení technické v Brně. Fakulta chemická. 2018.
Document type
Document version
Date of access to the full text
Language of document
cs
Study field
Chemie, technologie a vlastnosti materiálů
Comittee
doc. Ing. František Šoukal, Ph.D. (předseda)
prof. Ing. Jaromír Havlica, DrSc. (člen)
prof. Ing. Ladislav Omelka, DrSc. (člen)
prof. Ing. Petr Ptáček, Ph.D. (člen)
prof. Ing. Tomáš Svěrák, CSc. (člen)
doc. Ing. Lucy Vojtová, Ph.D. (člen)
doc. Ing. Marián Lehocký, Ph.D. (člen)
RNDr. Ladislav Pospíšil, CSc. (člen)
Date of acceptance
2018-06-12
Defence
Student velmi přehledně prezentoval výsledky své bakalářské práce. Oponent přítomen nebyl, ale jeho otázky byly uspokojivě diskutovány. Student problematice rozumí.
Otázky v diskusi:
Jak by se dal dále upravit povlak po temperaci?
Je lepší povlak před nebo po kalcinaci?
Otázky byly uspokojivě diskutovány.
Result of defence
práce byla úspěšně obhájena
Document licence
Standardní licenční smlouva - přístup k plnému textu bez omezení