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Materials - Contenido educativo

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Subido el 2 de noviembre de 2018 por Isabel L.

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Well, after writing, planning, it's a good idea to retake or review the different contents about materials and tools and I think we are going to do now. 00:00:03
It's important to know what is materials in technology. After that, we are going to explain the classification of materials and the properties of them. 00:00:25
and we'll do a small description about some of the most important materials 00:00:47
and after that I'm going to summarize 00:01:01
The main thing that usually we do in the workshop, when we are building our projects, are the 00:01:10
tools that usually we use and more or less workshop. 00:01:27
Firstly, obviously, everything is made by materials, things have a shape, a three-dimensional shape 00:01:36
and to do these shapes we need different parts 00:01:57
and each part is made with a typical material 00:02:12
nowadays for example plastics are very used in different things 00:02:18
for so many things 00:02:27
that is that materials indeed aren´t just only one substance 00:02:30
usually are a mixture of different substance. A substance is mainly 00:02:38
formed by just only one type of molecule and as you know the molecules are 00:02:49
are formed, are being, are being by the joint of different atoms. 00:03:01
So the complexity, the material are very complex. 00:03:19
but this complexity is made by mixtures of simple things 00:03:27
the particles such as electron or proton or neutron can be part of an atom 00:03:36
and the joint of different atoms with different chemical links makes the substance 00:03:56
and the mixture of different substances can form part of different materials, different technical materials 00:04:11
So, indeed, materials are very complex. 00:04:24
In order to ease our study, we will classify materials into two main categories, which 00:04:31
are methods and non-methods. 00:04:45
There are more than one classification. 00:04:50
This is one of the most important, but other possibility would be into structural and functional 00:04:55
materials, and it is also a technical classification. 00:05:15
Well, return to the main idea, materials can be classified into two different groups, which 00:05:21
are metals and non-metals. 00:05:31
Obviously, it is very easy to distinguish a metal and it is the main reason why we use 00:05:34
this kind of classification. 00:05:46
Another good reason is because the methyl link has a very specific and typical properties 00:05:49
as we will describe later. 00:06:05
Then methods can also be divided into ferrows and noferrows. 00:06:11
Well, indeed, there aren't any methods with 100% of the technical materials usually are 00:06:22
the solutions of a metal with other metals or no metals and it is very important to know. 00:06:46
When I say that a material is a metal, I'm saying really indeed that it is a dissolution 00:06:59
in which metal is solvent, so we can distinguish ferrous and no ferrous. 00:07:15
In ferrous the solvent is iron but the other substance usually is carbon and if the quantity 00:07:25
of carbon is less than 2%, then this is a steel, otherwise it is a steel. 00:07:41
To know Ferreira's materials, we can classify into two categories, which are light if its 00:07:57
density is less than titanium or heavy if its density is higher than titanium. 00:08:10
One example of light category would be titanium and also aluminium. 00:08:29
One example of heavy could be copper and its alloys, such as bronze and brass. 00:08:38
For non-metals materials there isn't any good classification. 00:08:54
People usually classify using their main uses, for example, materials for buildings, or material 00:09:06
for clothes, or materials for other things. 00:09:20
I classify non-metals into two good categories, which are natural and synthetic. 00:09:30
Obviously natural are not so natural, because for example marble or granite or clay 00:09:43
Usually are understood as natural materials, but obviously when I use one of these materials 00:09:56
It's not a raw material, it's a processed material, so it's the point, the characteristic 00:10:17
of technology. 00:10:34
synthetic materials are made in a in a laboratory also they don't they don't 00:10:37
they aren't in the nature you can find them in in the nature 00:10:56
For natural materials we can classify them into two different categories which are organic and inorganic. 00:11:02
And for synthetic materials also we classify into organic and inorganic. 00:11:16
The importance of the materials are because their properties, because they are used in the technological world 00:11:31
and the uses are connected with their properties 00:11:48
So we can classify the properties into three main categories, which are mechanical, physical and chemical. 00:11:52
One example of mechanical property could be a breaking strength or elasticity. 00:12:08
For physical properties, it could be a good example, density and conductivity. 00:12:19
And finally, for chemical properties, a good example obviously is the composition of these materials. 00:12:33
Well, we are now thinking in one of the materials that we have studied, we have studied in FestoFeso, which is good. 00:12:44
Good comes from trees, as we know, and trees are plants, so the good indeed comes from one part of a tree. 00:13:08
Good mechanical, not so many good mechanical properties, but it is very rigid, and has very good mechanical sizes. 00:13:35
On the other hand, apart from this, its density is very low and it has good insulation material, both electricity and heat. 00:13:53
and some of its uses are connected with this property. 00:14:15
Its chemical composition is lignin and cellulose. 00:14:25
Good can be divided into two main categories, which are natural and synthetic. 00:14:33
Natural wood can be soft, such as pine, or can be hard, such as oak. 00:14:43
And synthetic materials could be, for example, plywood, or chipboard, or particleboard. 00:14:57
For metals, which are other important group of materials, you can find it in the nature. 00:15:11
What you can find are the minerals. 00:15:38
So, we have to produce or to convert the minerals into our metals, alloys, and it is a very complex process. 00:15:45
but it depends of the metal you want to produce so it's different their main 00:16:05
properties would be is ducitilli they are very high density they are 00:16:23
They are solid, they are good conductors, they aren't insulated, they have a very typical 00:16:32
color and brightness and also they usually react with the oxygen and the reaction is 00:16:52
called metal oxidation. 00:17:12
Among the the main alloys of metals or metal alloys we can say that for example steel 00:17:19
which is a mixture of iron and carbon with less than two percent of carbon is a good example. 00:17:31
Another good example could be bronze, which is a mixture of copper and stannium, and another 00:17:40
brass, which is a mixture of copper and zinc, and other good example could be aluminium. 00:17:51
and there are a lot of metals, alloys, and there are a lot of different kinds of materials. 00:18:01
For example, there are a lot of building materials that could be natural or could be synthetic. 00:18:13
For example, clay and different kinds, different types of pebble, marble. 00:18:23
All of these are typical building materials. Also concrete and other building materials. 00:18:29
And plastics nowadays are one of the most interesting materials because it is used in a lot of objects, for example, bottles or different kind of objects are made by plastic. 00:18:44
and for example polystyrene is very important plastic and other important 00:19:09
group could be clothes and materials that usually are used to make clothes 00:19:21
such as cotton, linseed, etc. Well, we have to make different things and 00:19:29
it is necessary to give this the correct form and we need to cut and to change the shapes 00:19:51
of the materials and to do this we need tools. I think it's a good idea that we 00:20:16
remember the most important tools that we have already used in the workshop so for example 00:20:28
Well, here you can see the steel rule or the workshop rule, the tri-square, different types 00:20:39
of clams, the bees, you can see the names of scissors, saws, clipping box saws, for example, 00:20:56
limbs, the gum, the glue gum, a hammer, nails and different kind of brush. Well, we are going to do 00:21:10
an exercise in which you have to put names to different tools and to know 00:21:33
with with with to know their uses on the materials that they usually use this 00:21:44
this tool because the tool is connected with the material properties so it's 00:22:00
very necessary that we know each tool and its material and its tags 00:22:12
Today, that is all. Now we are going to do the activities. 00:22:27
Idioma/s:
en
Autor/es:
ISABEL LAFUENTE
Subido por:
Isabel L.
Licencia:
Reconocimiento - No comercial
Visualizaciones:
83
Fecha:
2 de noviembre de 2018 - 15:23
Visibilidad:
Público
Centro:
IES JAIME FERRAN
Duración:
22′ 36″
Relación de aspecto:
1.78:1
Resolución:
1920x1080 píxeles
Tamaño:
346.36 MBytes

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