Metals, Composites, and the Industrial Revolution
Metals
Metals are chemical elements that are good conductors of heat and electricity, typically solid at ordinary temperatures (except for mercury), and possess a characteristic brightness. Iron, calcium, and magnesium are abundant metals.
Properties
Metals are generally abundant, hard, and malleable. They conduct heat and electricity and can be combined to create alloys with enhanced properties. However, most metals are susceptible to corrosion, which can compromise the integrity of structures and machines.
Precious Metals
Precious metals are those found in their pure form in nature, not combined with other elements to form compounds. They are often used in jewelry and decorative arts.
What is Oxidation?
Oxidation is the process by which a metal returns to its natural state, as most metals are found in nature as oxides.
Bronze
Bronze is an alloy, a mixture of nine parts copper and one part tin. This combination creates a metal harder than its components and easier to melt and work with than copper alone.
Characteristics of the Bronze Age
Early Bronze Age
This period coincides with the Middle Minoan period in Greece, marked by palace construction and collective burials. Metal trading began in Cyprus and spread through the Aegean Sea.
Middle Bronze Age
Characterized by the destruction of Greek palaces and the rise of navigation for commercial purposes. Monumental buildings also appeared during this time.
Late Bronze Age
This era saw a transition towards the use of iron, beginning the Mycenaean period in Greece. This period involved significant cultural transformation, with precious metals appearing in tombs as symbols of power.
Iron Age
When did the Iron Age occur?
The Iron Age occurred during the last period of prehistory.
What was society like?
People lived in circular and square huts within walled areas. A social hierarchy existed, evidenced by burial mounds containing objects reflecting social status. Cremation in iron urns was also practiced, particularly in the Iberian Peninsula. Pottery was modeled by hand and decorated with geometric motifs.
What was iron used for? How was it obtained?
Iron was used for weapons and shields and was obtained by forging.
Main iron deposits in Spain
The main iron deposits are located in Murtal (Alhama de Murcia), Rambla de Algeciras (Alhama de Murcia), El Castellar (Librilla), La Jarosa II (Lorca), and Atapuerca (Burgos).
Where is iron obtained? What are its features?
Iron is obtained from pyrite and magnetite. It is a malleable, silver-gray metal with magnetic properties. It is ferromagnetic at room temperature and atmospheric pressure, extremely hard, and heavy.
Why did the use of bronze decline?
Bronze declined in use because iron was cheaper, more abundant, and more durable.
Composites
Composites are sophisticated materials that combine components like carbon fiber within a resin matrix. They are synthetic materials with unevenly mixed components, forming a compound. These components are of two types: cohesion and reinforcement.
Types of Composites
Cohesion: These components wrap and bind the reinforcement components, maintaining their position and providing stiffness.
Reinforcement: These components confer physical properties to the composite, enhancing cohesion and rigidity.
Advantages of Composites
Composites offer several advantages. Different reinforcing materials can be combined and applied in various directions, tailoring the material for specific applications. Composites can be very light, resist corrosion better than metal, are manufactured in molds, and do not experience metal fatigue. They also have a longer lifespan than aluminum and require less maintenance.
Sandwich Composites
Sandwich composites consist of two hard outer layers protecting an inner layer that provides structural properties. Safety glass, used in car windshields, is an example. The plastic sheet holds the glass shards together in case of an accident, protecting the occupants.
Industrial Revolution
Where did the Industrial Revolution begin? What transformations took place?
The Industrial Revolution began in the 17th century in Britain, leading to profound economic and social changes in Western Europe.
What was the most important technological innovation and its result?
The steam engine was the most important innovation, leading to increased trade and profits.
Changes during the Industrial Revolution
- Agricultural changes: Machines reduced the need for agricultural labor, leading to migration to cities. Fertilizers and new techniques were adopted.
- Business changes: Trade and profits increased due to machinery like the steam engine.
- Demographic changes: The population grew, nutrition improved, hygiene advanced, and people migrated from rural areas to cities.
Causes of the labor movement
Workers became aware of the need to unite and improve their poor working conditions.
Differences between the three industrial revolutions
1st Industrial Revolution (Coal): Machinery reduced labor needs, leading to unskilled, repetitive work, increased production, and higher profits. Capitalism and the proletariat emerged.
2nd Industrial Revolution (Electricity and Oil): Characterized by the use of electricity and oil, solidifying capitalism.
3rd Industrial Revolution (Scientific and Technological): This ongoing revolution began after World War II and coincides with a crisis in capitalism.