Advantages and disadvantages of electrometallurgy

Classified in Chemistry

Written at on English with a size of 4.32 KB.

 

5. Describe what is electrodeposition, describe the different Experimental methods. Give examples. Advantages and disadvantages. It is the process of production a coating, usually Metallic, on a surface by the action of an electric current._Experimental Methods::-Electroplating: It is a plating process in which metal ions in a Solution are moved by an electric field to coat an electrode. Metallic cations From a solution are reduced on a conductive object (to form a thin layer).-Electrophoretic Deposition:Colloidal particles suspended in a liquid migrate under the Influence of an electric field (electrophoresis) and are deposited onto an Electrode._Advantages: uniform coating thicknen,easy control,high speed of Coating and high pucity._Disadvantages:process is costly and time consuming,non-uniform Plating. _Examples:anticorrosion,automobile parts,metal furniture

6. Describe what is physical vapor deposition, Describe the different experimental methods. Give examples. Advantages and Disadvantages.It is a vaporisation coating technique, involving transfer of material On an atomic level. It is similar to CVD, except that the raw Materials/precursors starts out in solid form instead of starting out in Gaseous state._Methods::-Sputtering: is a technique used to deposit thin films Of a material onto a surface By first creating a gaseous plasma and then Accelerating the ions from this plasma into some source material.-Evaporation: The vacuum allows vapor particles to travel directly to the target object (substrate), where they condense back to a solid state._Examples:Thin film Solar panels._Advantages:Materials can be deposited with improved properties Compared to the substrate material.The process is more environmentally friendly Than processes such as electroplating._Disadvantages:High capital cost.The rate Of coating deposition is usually quite slow.

7. Describe what is hot-dip galvanizing. Give examples. Advantages and Disadvantages.It is the process of coating iron, steel or aluminium with a zinc layer. It is made by passing the workpiece through a malten bath of zinc at a high Temperature (460ºC), to form a stable and protective surface coating._Methods:Non-continuous Hot dip coating line,Continuous hot dip coating lines,Microstructure of the Coating._Advantages: It is a highly versatile process,Long life,It protects the Piece against corrosión._Disadvantages:The location of galvanizing plants is Limited,In-situ steelwork (existing structures),cannot be hot-dip Galvanizing._Examples:Pressed steel water tanks,Guardrails,Playground equipment.

8. What is SIMS? Advantages and limitations. Give Examples concerning engineering materialsSIMS: Secondary Ion Mass Spectrometry :analyzes the Composition of solid surfaces and thin films by sputtering the surface of the Specimen with a focused primary ion beam and collecting and analyzing ejected Secondary ions._Advantages:The analysis consumes very little sample,Samples With low concentration levels needed,No complex sample preparation needed._Limitations:Not All elements can be analysed,quantitatively,Expensive._Examples of application: Semiconductors, Superconductors, Glass, Stainless steel, Solid oxide fuel cells, Conservation science, Aerospace alloys, Biomaterials.

Entradas relacionadas: