Matterial science Essay Example

  • Category:
    Chemistry
  • Document type:
    Math Problem
  • Level:
    Masters
  • Page:
    1
  • Words:
    687

Material science

  1. Explain the flowing statements including , where appropriate , mechanisms and labeled diagrams showing clear structures

  1. Metals can fail either by brittle or ductile failure, whereas ceramics fail exclusively by a brittle mechanism.

The word failure when used on materials refers to the lack of the ability of the material to function normally. Failure could be caused by structural components, deformation or corrosion among other causes. The bonding of metals is weaker when compared to that of ceramics. Metals are known to have brittle and ductile failures hence when tension is applied on them they get deformed or break respectively. This is attributed to their weaker structural bonding which is covalent hence letting free movement of electrons between the atoms. The non-localized electrons in the metal structure are attributable to the brittle and ductile failures.

matterial science

On the other hand, ceramics are only brittle and break when tension is applied on them. However, they can be shaped into different shapes given their ductile capability. This is because of their ionic structure which gives them the aforementioned characteristics. The ionic structure is between a metal and non-metal thus making it stronger than that of metals.

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  1. can form 0,1,2 and 3- dimensional structures and the bonding in these materials changes the mechanical properties 4- 4SiO

Silicon combines with different quantities of oxygen to form silicates which apparently are the bigger portion of the earth’s crust. The silicate ion denoted as SiO44- forms a tetrahedral and has the ability of bonding with oxygen to form 0 to 3 dimensional structures all of which have different mechanical properties. When the silicate ion (SiO44- ) consists of a single ion it known as orthosilicate which is characteristic of a low melting point. For instance, salt is a bond of a single SiO44- with iron cation to form Fe2SiO4. Pyrosilicate (Si2O76 ) is the name given to two-dimensional silicate ion tetrahedral linked together. These have a slightly higher melting point than that of orthosilicates. They also have the ability of splitting along definite planes because of the layers as shown in the diagram below.

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Three dimensional framework of silicate ion tetrahedral are known as tectosilicates. These are characterized by fusion of all the four oxygen atoms in each tetrahedral. It is also important to note that in the event that there are more than two silicate ions, they form a ring and chain silicate which is an extremely hard compound. The number of SiO44 ranges from 3 to infinity. Quartz is an example of a three dimensional structure of the silicate ion.

  1. Give an example of a hard material and explain how its structure leads to its properties

Diamond is a perfect example of a hard material that is strong and difficult to break. Its hard characteristic is due to covalent bonding which form a three-dimensional structure. Such structures normally have four bonds that are surrounded by atoms to form a tetrahedron. In the case of diamond, one carbon atom shares electrons with other four covalent bonds forming a tetrahedral array which makes the diamond hard as shown in the diagram below.

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  1. Ceramic practices can incorporated into metals to produce cermets

EXPLIN how this is done, and how heterogeneity can impart enhanced properties

When ceramic particles are combined with metal matrix, they form cermets. This is done by grinding and milling the metal and ceramic into powder. The powders are spray dried to produce granules that are later pressed into a compact sheet (Brian 422). The sheet is sintered and ground to form a compact sheet which is known as the cermet. Cermets differ on the type of metal added to the ceramic.

Nevertheless, cermets have improved mechanical and physical properties than those of the original products hence heterogeneous. This is because they adopt the characteristics of metals and ceramics. For instance, they are hard and resistant to high temperatures. They also gain the ability to be deformed into different shapes without breaking. Ideal cermets are those whose metal proportion is less than 20%.

Work Cited

Mitchell, Brian. An introduction to materials engineering and science. 2004. Web. February

21, 2015. < http://fisica.ufpr.br/cmlepienski/brian.pdf>