1 00:00:03,180 --> 00:00:25,679 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. 2 00:00:25,679 --> 00:00:47,240 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. 3 00:00:47,240 --> 00:01:00,200 and we'll do a small description about some of the most important materials 4 00:01:01,320 --> 00:01:10,840 and after that I'm going to summarize 5 00:01:10,840 --> 00:01:27,920 The main thing that usually we do in the workshop, when we are building our projects, are the 6 00:01:27,920 --> 00:01:36,959 tools that usually we use and more or less workshop. 7 00:01:36,959 --> 00:01:57,609 Firstly, obviously, everything is made by materials, things have a shape, a three-dimensional shape 8 00:01:57,609 --> 00:02:12,449 and to do these shapes we need different parts 9 00:02:12,449 --> 00:02:18,449 and each part is made with a typical material 10 00:02:18,449 --> 00:02:27,449 nowadays for example plastics are very used in different things 11 00:02:27,449 --> 00:02:30,449 for so many things 12 00:02:30,449 --> 00:02:38,449 that is that materials indeed aren´t just only one substance 13 00:02:38,449 --> 00:02:47,250 usually are a mixture of different substance. A substance is mainly 14 00:02:49,169 --> 00:03:01,729 formed by just only one type of molecule and as you know the molecules are 15 00:03:01,729 --> 00:03:19,490 are formed, are being, are being by the joint of different atoms. 16 00:03:19,490 --> 00:03:27,490 So the complexity, the material are very complex. 17 00:03:27,490 --> 00:03:36,930 but this complexity is made by mixtures of simple things 18 00:03:36,930 --> 00:03:56,659 the particles such as electron or proton or neutron can be part of an atom 19 00:03:56,659 --> 00:04:11,159 and the joint of different atoms with different chemical links makes the substance 20 00:04:11,159 --> 00:04:24,160 and the mixture of different substances can form part of different materials, different technical materials 21 00:04:24,160 --> 00:04:31,939 So, indeed, materials are very complex. 22 00:04:31,939 --> 00:04:45,720 In order to ease our study, we will classify materials into two main categories, which 23 00:04:45,720 --> 00:04:50,850 are methods and non-methods. 24 00:04:50,850 --> 00:04:55,110 There are more than one classification. 25 00:04:55,110 --> 00:05:15,509 This is one of the most important, but other possibility would be into structural and functional 26 00:05:15,509 --> 00:05:21,949 materials, and it is also a technical classification. 27 00:05:21,949 --> 00:05:31,810 Well, return to the main idea, materials can be classified into two different groups, which 28 00:05:31,810 --> 00:05:34,569 are metals and non-metals. 29 00:05:34,569 --> 00:05:46,050 Obviously, it is very easy to distinguish a metal and it is the main reason why we use 30 00:05:46,050 --> 00:05:49,310 this kind of classification. 31 00:05:49,310 --> 00:06:05,149 Another good reason is because the methyl link has a very specific and typical properties 32 00:06:05,149 --> 00:06:11,810 as we will describe later. 33 00:06:11,810 --> 00:06:22,050 Then methods can also be divided into ferrows and noferrows. 34 00:06:22,050 --> 00:06:46,129 Well, indeed, there aren't any methods with 100% of the technical materials usually are 35 00:06:46,129 --> 00:06:59,649 the solutions of a metal with other metals or no metals and it is very important to know. 36 00:06:59,649 --> 00:07:15,370 When I say that a material is a metal, I'm saying really indeed that it is a dissolution 37 00:07:15,370 --> 00:07:25,769 in which metal is solvent, so we can distinguish ferrous and no ferrous. 38 00:07:25,769 --> 00:07:41,050 In ferrous the solvent is iron but the other substance usually is carbon and if the quantity 39 00:07:41,050 --> 00:07:57,879 of carbon is less than 2%, then this is a steel, otherwise it is a steel. 40 00:07:57,879 --> 00:08:10,560 To know Ferreira's materials, we can classify into two categories, which are light if its 41 00:08:10,560 --> 00:08:29,980 density is less than titanium or heavy if its density is higher than titanium. 42 00:08:29,980 --> 00:08:38,419 One example of light category would be titanium and also aluminium. 43 00:08:38,419 --> 00:08:54,809 One example of heavy could be copper and its alloys, such as bronze and brass. 44 00:08:54,809 --> 00:09:06,509 For non-metals materials there isn't any good classification. 45 00:09:06,509 --> 00:09:20,809 People usually classify using their main uses, for example, materials for buildings, or material 46 00:09:20,809 --> 00:09:30,330 for clothes, or materials for other things. 47 00:09:30,330 --> 00:09:43,330 I classify non-metals into two good categories, which are natural and synthetic. 48 00:09:43,330 --> 00:09:56,330 Obviously natural are not so natural, because for example marble or granite or clay 49 00:09:56,330 --> 00:10:17,570 Usually are understood as natural materials, but obviously when I use one of these materials 50 00:10:17,570 --> 00:10:34,070 It's not a raw material, it's a processed material, so it's the point, the characteristic 51 00:10:34,070 --> 00:10:37,230 of technology. 52 00:10:37,230 --> 00:10:53,230 synthetic materials are made in a in a laboratory also they don't they don't 53 00:10:56,830 --> 00:11:02,429 they aren't in the nature you can find them in in the nature 54 00:11:02,429 --> 00:11:16,429 For natural materials we can classify them into two different categories which are organic and inorganic. 55 00:11:16,429 --> 00:11:31,429 And for synthetic materials also we classify into organic and inorganic. 56 00:11:31,429 --> 00:11:48,200 The importance of the materials are because their properties, because they are used in the technological world 57 00:11:48,200 --> 00:11:52,399 and the uses are connected with their properties 58 00:11:52,399 --> 00:12:08,399 So we can classify the properties into three main categories, which are mechanical, physical and chemical. 59 00:12:08,399 --> 00:12:19,399 One example of mechanical property could be a breaking strength or elasticity. 60 00:12:19,399 --> 00:12:33,639 For physical properties, it could be a good example, density and conductivity. 61 00:12:33,639 --> 00:12:44,519 And finally, for chemical properties, a good example obviously is the composition of these materials. 62 00:12:44,519 --> 00:13:08,080 Well, we are now thinking in one of the materials that we have studied, we have studied in FestoFeso, which is good. 63 00:13:08,080 --> 00:13:35,830 Good comes from trees, as we know, and trees are plants, so the good indeed comes from one part of a tree. 64 00:13:35,830 --> 00:13:53,830 Good mechanical, not so many good mechanical properties, but it is very rigid, and has very good mechanical sizes. 65 00:13:53,830 --> 00:14:15,830 On the other hand, apart from this, its density is very low and it has good insulation material, both electricity and heat. 66 00:14:15,830 --> 00:14:25,830 and some of its uses are connected with this property. 67 00:14:25,830 --> 00:14:33,830 Its chemical composition is lignin and cellulose. 68 00:14:33,830 --> 00:14:43,830 Good can be divided into two main categories, which are natural and synthetic. 69 00:14:43,830 --> 00:14:57,330 Natural wood can be soft, such as pine, or can be hard, such as oak. 70 00:14:57,330 --> 00:15:11,330 And synthetic materials could be, for example, plywood, or chipboard, or particleboard. 71 00:15:11,330 --> 00:15:38,470 For metals, which are other important group of materials, you can find it in the nature. 72 00:15:38,470 --> 00:15:45,470 What you can find are the minerals. 73 00:15:45,470 --> 00:16:05,470 So, we have to produce or to convert the minerals into our metals, alloys, and it is a very complex process. 74 00:16:05,470 --> 00:16:23,230 but it depends of the metal you want to produce so it's different their main 75 00:16:23,230 --> 00:16:32,950 properties would be is ducitilli they are very high density they are 76 00:16:32,950 --> 00:16:52,259 They are solid, they are good conductors, they aren't insulated, they have a very typical 77 00:16:52,259 --> 00:17:12,880 color and brightness and also they usually react with the oxygen and the reaction is 78 00:17:12,880 --> 00:17:19,500 called metal oxidation. 79 00:17:19,500 --> 00:17:30,299 Among the the main alloys of metals or metal alloys we can say that for example steel 80 00:17:31,180 --> 00:17:40,859 which is a mixture of iron and carbon with less than two percent of carbon is a good example. 81 00:17:40,859 --> 00:17:51,980 Another good example could be bronze, which is a mixture of copper and stannium, and another 82 00:17:51,980 --> 00:18:01,859 brass, which is a mixture of copper and zinc, and other good example could be aluminium. 83 00:18:01,859 --> 00:18:13,880 and there are a lot of metals, alloys, and there are a lot of different kinds of materials. 84 00:18:13,880 --> 00:18:23,880 For example, there are a lot of building materials that could be natural or could be synthetic. 85 00:18:23,880 --> 00:18:29,880 For example, clay and different kinds, different types of pebble, marble. 86 00:18:29,880 --> 00:18:44,880 All of these are typical building materials. Also concrete and other building materials. 87 00:18:44,880 --> 00:19:09,240 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. 88 00:19:09,240 --> 00:19:21,180 and for example polystyrene is very important plastic and other important 89 00:19:21,180 --> 00:19:29,519 group could be clothes and materials that usually are used to make clothes 90 00:19:29,519 --> 00:19:51,950 such as cotton, linseed, etc. Well, we have to make different things and 91 00:19:51,950 --> 00:20:16,869 it is necessary to give this the correct form and we need to cut and to change the shapes 92 00:20:16,869 --> 00:20:27,589 of the materials and to do this we need tools. I think it's a good idea that we 93 00:20:28,950 --> 00:20:39,829 remember the most important tools that we have already used in the workshop so for example 94 00:20:39,829 --> 00:20:56,230 Well, here you can see the steel rule or the workshop rule, the tri-square, different types 95 00:20:56,230 --> 00:21:10,950 of clams, the bees, you can see the names of scissors, saws, clipping box saws, for example, 96 00:21:10,950 --> 00:21:33,869 limbs, the gum, the glue gum, a hammer, nails and different kind of brush. Well, we are going to do 97 00:21:33,869 --> 00:21:44,269 an exercise in which you have to put names to different tools and to know 98 00:21:44,269 --> 00:22:00,089 with with with to know their uses on the materials that they usually use this 99 00:22:00,089 --> 00:22:12,269 this tool because the tool is connected with the material properties so it's 100 00:22:12,269 --> 00:22:27,400 very necessary that we know each tool and its material and its tags 101 00:22:27,400 --> 00:22:33,880 Today, that is all. Now we are going to do the activities.