Effect of silver and tin addition on the properties of zinc alloy for giftware industry /
The application of Zinc based alloy in giftware industry instead of pewter is interesting since its price is less expensive. However, the use of Zinc alloy has some limitations such as mechanical properties and corrosion resistance. Therefore, modifying the properties of zinc based alloy is needed t...
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| Main Author: | |
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| Format: | Thesis |
| Language: | English |
| Published: |
Kuala Lumpur:
Kulliyyah of Engineering, International Islamic University Malaysia,
2013
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| Subjects: | |
| Online Access: | Click here to view 1st 24 pages of the thesis. Members can view fulltext at the specified PCs in the library. |
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| Summary: | The application of Zinc based alloy in giftware industry instead of pewter is interesting since its price is less expensive. However, the use of Zinc alloy has some limitations such as mechanical properties and corrosion resistance. Therefore, modifying the properties of zinc based alloy is needed to get the same properties as reference alloy (pewter) for giftware material. This work focused on introducing alloy with low the melting temperature, improving the mechanical properties and enhancing the corrosion resistance of Zn based alloy by adding Ag (0.03 wt.%, 0.27 wt.% , 0.50 wt.%) and Sn (1 wt.%, 8 wt.%, 15 wt.%). The samples were prepared by melting the zinc at desired temperature then the alloying elements were added before poured into a mold to produce specimens with standard size. Mechanical properties were studied based on its tensile strength and elongation. Fractography of the tensile specimen was further observed by using Scanning Electron Microscope (SEM). Furthermore, the effect of Sn and Ag on melting temperature was investigated. Microstructure was revealed by using Optical Microscope. The results show that increasing Ag and Sn addition give significant effect on the improving of tensile strength and elongation of the Zinc based alloy. The fracture surface of the tensile test specimen showed a mixed mode of fracture exhibiting ductile failure and brittle failure. Alloy with higher content of Ag (0.50 wt.%) and Sn (15 wt.%) tends to have more ductile failure then the brittle one. Microstructure observation shows the present of Ag3Sn intermetallic compounds which are expected to influence the mechanical properties and corrosion resistance of the alloys. Meanwhile, the electrochemical and corrosion behaviour of Zn alloy were investigated in dishwasher detergent and water solution by using Tafel. The sample surface was characterized using X-Ray diffraction (XRD) and Scanning Electrone Microscope (SEM). The results reveal that addition of Ag is significant to reduce the corrosion rate rather than Sn. The protective passive layers are formed on surface of alloy with higher content of Ag and Sn. The products of the passive layer are Zinc oxide (ZnO) and Zinc hydroxide (Zn(OH)2). In other words, the effect of increasing content of Ag and Sn will produce alloy with low melting temperature, better tensile strength, elongation, ductility and low corrosion rate. The developed alloy shows the possibility to be used as raw material for giftware since its properties is closed to the properties of the present material used. |
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| Physical Description: | xvi, 143 leaves : ill. ; 30cm. |
| Bibliography: | Includes bibliographical references (leaves 133-141). |