1 00:00:14,849 --> 00:00:19,809 Este video está dirigido a monchis 2 00:00:19,809 --> 00:00:25,089 materials. In this video we'll discuss the materials used in mechanical manufacturing 3 00:00:25,089 --> 00:00:30,370 with the aim of achieving the objective of making an appropriate selection of them. 4 00:00:34,640 --> 00:00:40,799 If we look around us we can find multiple objects that we use for a multitude of applications 5 00:00:40,799 --> 00:00:46,880 in which the choice of materials is fundamental as the reparation will depend on them. 6 00:00:47,039 --> 00:00:53,200 The choice of materials significantly influences their quality, durability, functionality, and cost. 7 00:00:53,539 --> 00:00:58,340 By choosing the right materials, more efficient, durable, and sustainable products can be created, 8 00:00:58,500 --> 00:01:05,060 ensuring efficiency, durability, and sustainability, and can source customer satisfaction as well as user safety. 9 00:01:05,980 --> 00:01:11,659 Some important reasons for choosing the right materials when manufacturing a product are durability. 10 00:01:11,659 --> 00:01:18,659 Choosing durable materials can increase the product's lifespan and reduce the need for frequent repairs and replacements. 11 00:01:18,659 --> 00:01:19,659 Functionality 12 00:01:19,659 --> 00:01:27,659 The right materials can enhance the product's functionality, making them easier to use and more efficient in their performance. 13 00:01:27,659 --> 00:01:28,659 Aesthetics 14 00:01:28,659 --> 00:01:37,659 Materials also influence the appearance and visual appeal of the product, so it is important to choose materials that fit the desired design and style. 15 00:01:37,659 --> 00:01:38,659 Quality 16 00:01:38,659 --> 00:01:58,000 Quality. High-quality materials are essential for ensuring the quality of products. Low-quality materials can make the product less durable, less efficient and more prone to fail. Cost. Choosing the right materials can help reduce production costs and make the product more affordable for customers. 17 00:01:58,000 --> 00:02:10,000 Sustainability. Selecting sustainable materials can reduce the environmental impact of production and enhancing the brand's image. 18 00:02:10,000 --> 00:02:16,000 The chemical composition of materials begins with their smallest particles, atoms. 19 00:02:16,000 --> 00:02:26,759 Within them, there are two distinctive particles, the nucleus composed of protons and neutrons and the outer shell comprising electrons. 20 00:02:26,759 --> 00:02:35,199 As we already know, the periodic table is a very useful table for organizing elements that help us understand the chemistry and behavior in various situations. 21 00:02:35,199 --> 00:02:43,780 By knowing all elements, the elements positioned on the table, we can predict its chemical properties and its reactivity with other elements. 22 00:02:46,360 --> 00:02:51,360 Chemical bonds are the key to the formation of solid and stable materials. 23 00:02:51,360 --> 00:03:03,840 Atoms bond with each other through chemical bonds, which are forces that hold atoms together in a molecule or compound, as when a bond forms, the energy state becomes more stable. 24 00:03:04,379 --> 00:03:09,300 There are three main types of chemical bonds, ionic, covalent and metallic. 25 00:03:12,680 --> 00:03:22,780 Anionic bond atoms join because one of them loses electrons and becomes a positive ion, while the other atom gains electrons and becomes a negative ion. 26 00:03:22,780 --> 00:03:27,780 Oppositely shared ions attract each other and are held together in ionic crystals. 27 00:03:27,780 --> 00:03:36,780 Materials bonded by ionic bonds have characteristic properties such as high melting point and boiling point, and they are crystalline solids at room temperature. 28 00:03:36,780 --> 00:03:44,780 Common examples of materials bonded by ionic bonds include sodium chloride, known to all as table salt. 29 00:03:44,780 --> 00:03:55,280 Covalent bonding occurs when one or more atoms share electrons to form a molecule, achieving a much more stable electronic configuration. 30 00:03:55,280 --> 00:04:01,280 It forms between atoms with very similar electronegativity, which are close in the periodic table. 31 00:04:01,280 --> 00:04:10,280 For example, in the water molecule, the two hydrogen atoms share electrons with the oxygen atom in order to provide stability to it. 32 00:04:10,280 --> 00:04:21,100 In a metallic bond, metallic atoms share their electrons in a crystalline structure where electrons move freely between atoms. 33 00:04:21,100 --> 00:04:30,610 This type of bond is responsible for the physical properties of metals, such as electrical and thermal conductivity. 34 00:04:30,610 --> 00:04:35,610 The solid state is characterised by the more or less rigid shape it adopts. 35 00:04:35,610 --> 00:04:44,610 The crystalline and amorphous solid state, the forms in which matter can exist, differ mainly in their molecular structure and organization. 36 00:04:44,610 --> 00:04:55,610 The crystalline solid state is the one in which particles are arranged in an ordered and regular manner in a repetitive three-dimensional pattern that extends in all directions. 37 00:04:55,610 --> 00:05:00,649 On the other hand, in the amorphous solid state, the particles don't have a regular 38 00:05:00,649 --> 00:05:06,550 organization in 3D space, instead of a repetitive and ordered structure. 39 00:05:06,550 --> 00:05:10,629 The particles are arranged in a random and disordered manner. 40 00:05:10,629 --> 00:05:12,769 Amorphous materials don't have a defined shape. 41 00:05:12,769 --> 00:05:18,629 They have lower melting points than crystalline materials and exhibit mechanical and electrical 42 00:05:18,629 --> 00:05:23,829 properties that don't depend on the direction. 43 00:05:23,829 --> 00:05:29,870 As we'll see in later videos associated with the teaching unit, the microscopic properties 44 00:05:29,870 --> 00:05:32,829 of materials depend on how atoms are arranged. 45 00:05:32,829 --> 00:05:38,430 In general, the structure of materials at a microscopic and molecular level affects 46 00:05:38,430 --> 00:05:41,410 their microscopic properties in several ways. 47 00:05:41,410 --> 00:05:46,009 For example, a material with a crystalline structure typically has a higher density and 48 00:05:46,009 --> 00:05:52,750 is harder and more resistant than a material with an amorphous structure. 49 00:05:52,750 --> 00:05:58,069 The crystalline structure of atoms can be described in terms of a 3D crystal net composed 50 00:05:58,069 --> 00:06:05,550 of a series of repetitive unit cells in which the atoms assume relatively fixed positions. 51 00:06:05,550 --> 00:06:11,689 Each unit cell contains one or several atoms and repeats in 3D space to form the complete 52 00:06:11,689 --> 00:06:14,430 crystalline structure. 53 00:06:14,430 --> 00:06:17,569 Most metals crystallize in three structures. 54 00:06:17,569 --> 00:06:25,600 body center cubic, face center cubic and axonal closed pact. The structures they crystallize 55 00:06:25,600 --> 00:06:31,680 in are those that correspond to lower energy levels and are therefore more stable.