General information about materials, their structure and properties. Mechanical properties of materials

Kazakova Z.K.

Project for children 4-5 years old

"Properties and qualities of materials"

PROBLEM:

Children under the concept of "material" mean only fabric. Although most objects are made from materials such as plastic, glass, wood, paper man-made world surrounding us. Children do not know about the properties of these materials, the peculiarities of handling them, do not know their intended purpose and the functions of objects made from them.

PURPOSE:

To form in children ideas about such materials of the man-made world as paper, plastic, wood, glass.

TASKS:

1. Teach children to identify signs of materials, their properties and qualities; to classify objects of the man-made world by material.

2. To acquaint children with the purpose of the objects of the man-made world, depending on the properties and qualities of the material from which they are made.

3. Make up with children rules for handling objects, depending on the material from which they are made.

4. Organize the activities of children to create a collection of "Variety of paper".

5. Expand and activate the children's vocabulary by the characteristics of the characteristics of the materials of the man-made world.

6. To develop the social skills of children: the ability to work in a group, negotiate, take into account the opinion of a partner.

EVENTS:

1. Collecting materials for the project's piggy bank.

2. Cognitive lessons on the following topics:

· "History of the discovery of glass"

· "Paper making"

· "The transformation of wood into building material"

· "The appearance of plastic"

3. Guessing riddles and reading fiction about various materials and objects of the man-made world made of them.

4. Artistic and creative activity:

· Making paper lanterns for the Christmas tree by children;

· Production of "hare ears" hats from cardboard.

5. Organization of the role-playing game "Shop" ("Furniture", "Toys", "Dishes", "Stationery")

6. Organization of the didactic game "My apartment".

7. Conducting experiments:

· "Sinking - not sinking"

· "Beats - not beats"

· "What can be seen through glass (transparent, frosted, colored)"

· "Wrinkles - does not wrinkle"

8. Organization of an exhibition of objects of the man-made world made of paper, plastic, wood, glass.

STAGES OF WORK ON THE PROJECT

Istage - PIGGER

v objects of the man-made world (made of paper, wood, plastic, glass);

v illustrations of various objects of the man-made world (made of paper, wood, plastic, glass);

v artistic word about materials and objects of the man-made world (poems, riddles, sayings, stories, etc.).

IIstage - CREATING A CARD ROOM

Algorithm for creating a filing cabinet

Objects of the man-made world made of paper

Objects of the man-made world made of wood

Objects of the man-made world made of plastic

Objects of the man-made world made of glass

IIIstage - MODEL

Based on the knowledge gained, the "Model of man-made materials" was developed together with the children.

IVstage - PRODUCT

The product of this project is an exhibition of objects of the man-made world from various materials: "Plastic Kingdom", "Glass Kingdom", "Wooden Miracle", "Paper Country".

Vstage - PROJECT PRESENTATION

Children of group 11 are invited.

Children - participants of the project tell:

- There are many materials in the world: plastic, glass, wood, paper. We assembled a piggy bank of items from these materials, then distributed them into boxes - we created a card index based on the materials. And today we present you with their exhibition.

Dear guests, please come to our exhibition.

The children of the group and guests come to the table with plastic objects.

“This is the Kingdom of Glass.

Children talk about the signs of glass and recite poetry:

You can see everything through the glass:

And the river, and the meadows,

Trees and cars

People, dogs, houses.

With a glass bunny

I love to play.

I know he's fragile

I won't drop it.

Fragile, transparent,

Solid in appearance.

It will close from the wind

Insulate from the cold.(Glass)

The children of the group and guests come to the table with wooden objects.

- This is the exhibition "Wooden Miracle".

Children talk about the signs of a tree and recite poems:

Wooden box

Stands on the bedside table.

Mommy beloved

She keeps the rings in it.

Wooden chest

So beautiful and bright.

Daddy is often out of it

Pulls out a gift.

A painted plaque hangs,

She is a helper, we know:

She helped us cut vegetables,

That's what it is for.

The children of the group and guests come to the table with objects made of paper.

- This is the exhibition "Paper Country".

Children talk about the signs of paper and read poems:

Paper butterflies,

Paper elephants

Bunnies and Christmas trees

Children need it so much!

Paper boats

I like to start it myself.

Paper boats

They float along the streams.

Song "Paper country"

(music. I. Nikolaev)

There are over the seas, over the mountains

Paper country.

There are streets and walls made of paper

Furniture and all houses.

Residents wear out of paper

Hats and umbrellas.

The world of paper is ruled

Paper adults.

Chorus: Paper country,

Paper country.

We will tell you

We will show you

Here she is, here she is!

(Children point to "Paper Country")

CONTINUATION OF THE PROJECT

Acquaintance of children with other materials of the man-made world, such as fabric, metal, rubber, polyethylene.

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Students, graduate students, young scientists who use the knowledge base in their studies and work will be very grateful to you.

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General information about materials, their structure and properties

General information about materials.

All materials on a chemical basis are divided into two main groups - metallic and non-metallic.

Metals include metals and their alloys. Metals make up more than 2/3 of all known chemical elements. Metallic materials are classified as ferrous and non-ferrous. Iron and its alloys - steel and cast iron - are ferrous. All other metals are non-ferrous. Pure metals have low mechanical properties compared to alloys, and therefore their use is limited to those cases where it is necessary to use their special properties.

Non-metallic materials include various plastics(layered, fibrous, powder, gas-filled), rubber materials, wood materials(lumber, wood veneer), textile materials, inorganic (ceramics, glass) and composite materials.

The practical significance of different materials is not the same. Ferrous metals are most widely used in technology. More than 90% of all metal products are made on the basis of iron. However, non-ferrous metals have a number of valuable physical and chemical properties that make them irreplaceable. Non-metallic materials also take a place in the industry, but their use is small (about 10%) and the prediction of thirty years ago that non-metallic materials would significantly press the metallic ones by the end of the century did not come true. In other areas, the use of different metal materials is currently developing at a faster pace than metal materials.

The structure of materials.

All solids are divided into amorphous and crystalline.

In amorphous bodies, atoms are arranged chaotically, i.e. in disorder, without any system, therefore, when heated, the bodies soften in a large temperature range, become viscous, and then turn into a liquid state. When cooled, the process goes in the opposite direction. Examples of amorphous bodies are glass, glue, wax, rosin, i.e. the amorphous structure is inherent mainly in non-metals.

In crystalline bodies, atoms are arranged in a strictly defined sequence. The bodies remain solid, i.e. keep the shape given to them up to a certain temperature at which they turn into a liquid state. When cooled, the process goes in the opposite direction. The transition from one state to another occurs at a certain melting point. Bodies with a crystalline structure include table salt, quartz, granulated sugar, metals and alloys.

Atomic-crystal structure - the mutual arrangement of atoms in a crystal. A crystal consists of atoms (ions) arranged in a certain order, which is periodically repeated in three dimensions. The smallest complex of atoms, which, with repeated repetition in space, makes it possible to reproduce a spatial crystal lattice, is called an elementary cell. For simplicity, it is customary to replace the spatial image with schemes where the centers of gravity of the particles are represented by dots. At the points of intersection of straight lines, atoms are located; they are called lattice nodes. The distances between the centers of atoms located in neighboring lattice sites are called parameters, or lattice periods.

An ideal crystal lattice is a multiple repetition of unit crystal cells. A real metal is characterized by the presence of a large number of structural defects that violate the periodicity of the arrangement of atoms in the crystal lattice.

There are three types of defects in the crystal structure: point, linear and surface. Point defects are characterized by small sizes, their size does not exceed several atomic diameters. Point defects include: a) free places in the nodes of the crystal lattice - vacancies (Schottky defects); b) atoms displaced from the sites of the crystal lattice into interstitial spaces - dislocated atoms (Frenkel defects); c) atoms of other elements located both in the nodes and in the interstices of the crystal lattice - impurity atoms. Linear defects are characterized by small dimensions in two dimensions, but have significant extension in the third dimension. Most important species linear defects - dislocations (Latin dislocation - displacement). Surface defects are thin and large in the other two dimensions. Usually these are the places where two oriented sections of the crystal lattice meet. They can be grain boundaries, fragment boundaries within a grain, block boundaries within fragments.

The properties of materials directly depend on the structure and defects.

Material properties.

Physical properties determine the behavior of materials in thermal, gravitational, electromagnetic and radiation fields. Of the important physical properties, one can single out thermal conductivity, density, coefficient of linear expansion.

Density is the ratio of the mass of a homogeneous material to a unit of its volume. This property is important when using materials in aviation and rocket technology, where created structures should be lightweight and durable.

The melting point is the temperature at which a metal changes from a solid to a liquid state. The lower the melting point of the metal, the easier the processes of its melting, welding, and the cheaper they are.

Electrical conductivity is the ability of a material to conduct well and without loss of heat generation electricity... Metals and their alloys, especially copper and aluminum, have good electrical conductivity. Most non-metallic materials are not capable of conducting electrical current, which is also an important property used in electrical insulating materials.

Thermal conductivity is the ability of a material to transfer heat from warmer parts of bodies to less heated ones. Metallic materials are characterized by good thermal conductivity.

Magnetic properties i.e. only iron, nickel, cobalt and their alloys have the ability to be well magnetized.

The coefficients of linear and volumetric expansion characterize the ability of a material to expand when heated.

Chemical properties characterize the tendency of materials to interact with various substances and are associated with the ability of materials to withstand the harmful effects of these substances. The ability of metals and alloys to resist the action of various non-invasive environments is called corrosion resistance, and the similar ability of non-metallic materials is called chemical resistance.

Mechanical properties characterize the ability of materials to resist action external forces... The main mechanical properties include strength, hardness, impact strength, elasticity, plasticity, brittleness, etc.

Strength is the ability of a material to resist the destructive effects of external forces

Hardness is the ability of a material to resist the introduction of another, more solid under load.

Viscosity is the property of a material to resist destruction under dynamic loads.

Elasticity is the property of materials to regain their size and shape after the termination of the load.

Plasticity is the ability of materials to change their size and shape under the influence of external forces, without collapsing.

Brittleness is the property of materials to collapse under the action of external forces without permanent deformation.

Technological properties determine the ability of materials to undergo different kind processing. Foundry properties are characterized by the ability of metals and alloys in the molten state to fill well the cavity of the casting mold and accurately reproduce its shape (fluidity), the amount of volume reduction during solidification (shrinkage), the tendency to form cracks and pores, and the tendency to absorb gases in the molten state.

The operational (service) properties include heat resistance, heat resistance, wear resistance, radiation resistance, corrosion and chemical resistance, etc.

Heat resistance characterizes the ability of a metallic material to resist oxidation in a gas atmosphere at high temperatures.

Heat resistance characterizes the ability of a material to maintain mechanical properties at high temperatures.

Wear resistance is the ability of a material to resist the destruction of its surface layers by friction.

Radiation resistance characterizes the ability of a material to resist the effects of nuclear radiation.

Question 2: Classification of textile fibers.

Textile fiber is an elongated body, flexible and strong, with small transverse dimensions, limited length, suitable for the manufacture of yarns and textile materials.

The classification of fibers is based on their chemical composition and origin.

Depending on the origin, textile fibers are divided into natural and chemical.

Natural fibers include fibers of plant, animal and natural origin, which are formed in nature without direct human participation. Natural plant fibers are composed of cellulose; they are obtained from the surface of seeds (cotton), fruits (coir), from stems (flax, ramie, hemp, jute, etc.) and plant leaves (abaca, sisal). Natural fibers of animal origin are composed of proteins - keratin (wool of various animals), or fibroin (silk of a mulberry or oak silkworm).

Chemical fibers include fibers created in the factory by molding from organic natural or synthetic polymers or inorganic substances. According to their composition, chemical fibers are divided into artificial and synthetic.

Artificial fibers are obtained from high molecular weight compounds found in finished form (cellulose, proteins). They are obtained by chemical processing of natural polymers of plant and animal origin, from waste from the cellulose production and food industry.

A polymer is a substance whose molecules consist of a large number of repeating units. The raw materials for polymers are wood, seeds, milk, etc. Textile materials based on artificial cellulose fibers, such as viscose, polynose, copper-ammonia, triacetate, and acetate, are most widely used in the garment industry.

Synthetic fibers are produced by chemical synthesis of polymers, i.e. creation of substances with a complex molecular structure from simpler ones, most often from petroleum products and coal... These are polyamide, polyether, polyurethane fibers, as well as polyacrylonitrile (PAN), polyvinyl chloride (PVC), polyvinyl alcohol, polyolefin. Also, according to their composition, synthetic fibers are divided into carbon-chain and hetero-chain. Heterochain fibers are formed from polymers, the main molecular chain of which, in addition to carbon atoms, contains atoms of other elements. Carbochain fibers are those that are obtained from polymers having only carbon atoms in the main chain of macromolecules.

material property structure defect

Used Books

1. Yu.P. Solntsev Materials Science. Application and selection of materials: Textbook / Solntsev Yu.P., Borzenko E.I., Vologzhanina S.A. - SPb .: KHIMIZDAT, 2007 .-- 200 p.

2. Buzov B.A. Materials science in the manufacture of products light industry(sewing production): Textbook for students. higher. study. institutions / B.A. Buzov, N. D. Adymenkova: Ed. B.A. Buzova. - M .: Publishing Center "Academy", 2004 - 448 p.

3. Savostitsky N.A. Materials science of sewing production: a textbook for students. institutions of environments. prof. education / N.A. Savostitsky, E.K. Amirova. - 7th ed., Erased. - M .: Publishing Center "Academy", 2013. - 272 p.

4. Metals and alloys. Reference book / V. K Afonin et al. - NPO "Professional" SPb, 2003 - 200 p.

5. Yu.P. Solntsev "Materials Science" / Yu.P. Solntsev, E.I. Pryakhin - SPb .: Khimizdat, 2007, 783p.

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