THE MATERIALS, NATURAL AND ELABORATED
THE MATERIALS, NATURAL AND ELABORATEDMATERIALSThere are useful
substances that serve to us to make the objects that surround us.In
the ambience of the construction, a material can be a matter block
or a component that is used to build already is a building or any
other construction.The use that is given to the term in the
engineering, defines to the materials like substances with useful
qualities that can be thermal, mechanical or of another class.
THE MATERIALS CAN QUALIFY ACCORDING TO ITS ORIGINNatural
materials or raw material: They are those that are obtained
straight of the nature, like plants, animals, rocks and soil. They
are used such a which as they are, without suffering alterations
provoked by the man, for example: sand, water, stones, oil, wool,
wood, cotton, rubber, etc.Elaborated or artificial materials: Those
natural materials that they need from a transformation process to
be able to be used, like the role, pasteboard, concrete, plastic,
gum, nylon and leather.
NATURAL MATERIALS VEGETABLE ORIGINThe materials of vegetable
origin are obtained of the plants. For example, the cotton and the
wood.
NATURAL MATERIALS ANIMAL ORIGINThe materials of animal origin
come from the animals. For example, the leather that is obtained of
the skin of the animals and the silk that is obtained of the
silkworms.
NATURAL MATERIALS MINERAL ORIGINThe materials of mineral origin
are obtained of minerals and rocks. For example, the iron and the
marble, not ferric metals (copper, lead, aluminum, zinc)
WOODComposition: The wood is composed basically by cellulose (50
to 60 %),(15 to 25 %) that is the one that gives rigidity and
hardness to the tree and others like resin, starch, tannins, water,
etc. Properties of the wood: The wood has a fibrous structure in
which its cells gather together in sense parallel to the axis of
the tree. This awards an anisotropic behavior. Hardness: It is the
biggest or least resistance that there put up the bodies to be
infuriated or penetrated. The fibrous wood is the hardest and the
softest porous ones. The hardest it has dark tones and rings of
very together growths. Mechanical resistance: Aptitude of a
material to support efforts without be deforming nor to break.
MECHANICAL PROPERTIES OF THE WOODTypes of efforts 1 Haulage. It
takes place when on a material they operate two forces that there
has the same direction and opposite sense that tend to stretch it.
The wood has a high resistance to the haulage in the direction
parallel to the fibre and very low in direction perpendicular to
her. 2. Compression. It takes place when on a material they operate
two forces that have the same direction and opposite sense that
tend to squash it. The wood has a resistance to the compression
raised in the direction parallel to the fibre and goes down in the
sense perpendicular to her. 3. Push-up. It takes place when on a
material they operate the combined effects of haulage and
compression on opposite faces of the same one In general, the wood
resists very well the push-up efforts, especially the young and
green wood
4. Cizalladura. It takes place when on a material they operate
two equal forces with the same direction and the opposite sense
placed in the same plane and acting in the plane of section of the
material tending to cut it. The wood has a resistance to the
cizalladura very low in direction parallel to the fibre and a
resistance moderated in the perpendicular direction. 5 Torsion. It
takes place when on a material they operate two equal forces with
the same direction and sense, placed in parallel planes and acting
in the plane of section of the element. Electrical and thermal
properties: The wood is a good electrical and thermal insulator
when it is dry.
ALUMINUMMetallic chemical element, from symbol To, atomic number
13, atomic weight 26.9815, which belongs to the group IIIA of the
periodic system. The pure aluminum is soft and it has mechanical
resistance small, but it can form alloys with other elements to
increase its resistance and to acquire several useful properties.
The aluminum alloys are light, strong, and of easy formation for
many metalwork processes; they are easy to assemble, to melt or to
plot and they accept big variety of finished. For its physical,
chemical and metallurgical properties, the aluminum has turned into
not ferrous metal of major use.The aluminum is the most abundant
metallic element in the Earth and in the Moon, but it is never in
free form in the nature. Silicate is distributed extensively in the
plants and in almost all the rocks, especially in the igneous ones,
which contain aluminum in the shape of aluminum minerals.
COPPERChemical element, of symbol Cu, with atomic number 29; one
of the metals of transition and important not ferrous metal. Its
utility owes to the combination of its chemical, physical and
mechanical properties, as well as to its electrical properties and
its plenty. The copper was one of the first metals used by the
human beings.Most of the copper of the world is obtained of the
mineral sulfides like the calcocita, covelita, calcopirita, bornita
and enargita. The rusty minerals are the cuprite, tenorita,
malachite, blue stone, crisocola and brocantita. The natural
copper, earlier abundant in the United States, is extracted now
only in Michigan. The grade of the mineral used in the production
of copper has been diminishing regularly, the same way as the
richest minerals have become exhausted and the copper demand has
grown. There are large numbers of copper in the Earth for future
use if there are used the minerals of the lowest grades, and there
is no probability of which they become exhausted during a long
period.
ZINC The zinc is a color metal between bluish target and silver
gray. It is hard and fragile to most of temperatures, but it is
possible to do malleably for warming to between 100 and 150 grades
Celsius.The zinc is used principally like an anticorrosive agent in
metal products. It is used in the galvanization process. The
galvanization is the recovering of other metals with iron or steel.
Approximately half of the zinc that is used in the world is for
galvanization. The galvanization is used to make metallic cloth,
rails, suspension bridges, posts of light, metal roofs,
interchangers of heat and bodyworks of cars. The zinc is used like
a plate in other metals, in particular the metals that are used in
electrical works or that contact sea water.
MECHANICAL PROPERTIES OF THE
METALSResstanseFragilityColabilidadTenacityResilienceFatigueDuctilityMaquinabilidadFluenciaMalleabilityHardnessElasticityPlasticity(ARTIFICIAL)
ELABORATED MATERIALS
They are those that we make the persons. For it, we use natural
materials that then we turn in artificial. For example, with the
wood we make role and with minerals we make glass.
(ARTIFICIAL) ELABORATED MATERIALS
The plastic and the pasteboard are artificial materials. The
plastic ones are made by oil and the pasteboard is made by
wood.
STEEL The steel is basically an alloy of combination of iron and
carbon (about 0.05 % even less than 2 %). Sometimes other specific
alloy elements such like the Cr (chromium) or they do not even join
with certain intentions.
CLASSIFICATION OF THE STEELThe different types of steels qualify
in accordance with the elements of alloy that produce different
effects in the steel.Alloyed steelsThese steels contain a certain
proportion of vanadium, molybdenum and other elements, in addition
to major quantities of manganese, silicon and copper that the
normal carbon steels.
CLASSIFICATION OF ALLOYED STEELSStructural:It is those steels
that are used for diverse parts of machines, such as cogwheels,
axes and levers. Also they are used in the structures of buildings,
construction of chassis of motorcars, bridges, ships. The content
of the different alloy from 0.25 % to 6 %.For hardware:Steels of
high quality that are used in hardware to cut and to mold metals
and non-metals. Special: the special alloy steels are the stainless
and those steels with a content of chromium generally superior to
12 %. These steels of big hardness and high resistance to the high
temperatures and to the corrosion.
STAINLESS STEELSThe stainless steels contain chromium, nickel
and other elements of alloy, which they keep brilliant to the rust
and oxidation in spite of the action of the moisture or of acids
and corrosive gases. Some stainless steels are very hard; others
are very resistant and they maintain this resistance during long
periods to extreme temperatures. The stainless steel is used for
the tubes and tanks of refineries of oil or chemical plants.
STEELS TO THE COALMore than 90 % of all the steels is steels to
the coal. These steels contain diverse quantities of carbon and
less than 1.65 % of manganese, 0.60 % of silicon and 0.60 % of
copper. Between the made carbon steels products they represent
machines, bodyworks of motorcar, most of the structures of
construction of steel, ships helmets.
CLASSIFICATION OF STEELS TO THE COALI steel to the low carbon:
also acquaintance as the soft or sweet steel has less than 0.30 %
of carbon.I steel to the half carbon: it has from 0.30 % 0.60 % of
carbon. It is generally used in applications that need a higher
resistance.I steel to the high carbon: it has more than 0.60 % of
carbon. It is used in general for parts that need mechanical
resistance, hardness, and resistance to the wear.
BRASS
The brass, it is an alloy of Copper and Zinc that is realized in
crucibles or in a stove of reverbero to a temperature of smelting
of approximately 980 C. The proportions of Copper and Zinc can be
changed to create a brasses status with variable properties. In the
industrial brasses the percentage of Zn is always supported between
30 and 40 %. Its composition influences the mechanical
characteristics, the fusibility, and the capacity of shape for
smelting, forge, printing and mechanized.
USES OF THE BRASSa) Car partsb) Pieces for machinery in
general.c) Bomb valves of high and low pressure, rotores,
accessories for steam, cushions of friction, bars of slide d)
Bulonera: nuts, screws and washers. e) Pieces manufacture for armed
with products industrialized in general. f) Manufacture of padlocks
and locks. Electrical.a) Morsetera
GLASS
Glass (industry), amorphous substance made especially from
silica (SiO2) melted to high temperatures with boratos or
phosphate. Also a volcanic material is in the nature, for example
in the obsidian, or in the enigmatic well-known objects as
tectitas. The glass is an amorphous substance because it is neither
a solid one nor a liquid, but it is in the glassy state in which
the molecular units, although they are ready of untidy form, have
cohesion sufficient to present mechanical rigidity. The glass cools
down up to hardening without crystallization taking place; the
warming can return him its liquid form. It is usually transparent,
but also it can be translucent or opaque. Its color changes
according to the ingredients used in its manufacture.The ruined
glass is malleable and it is possible to give him form by means of
diverse skills. In cold, it can be carved. To low temperatures it
is fragile and it breaks with conchoidal break (in the shape of sea
conch).
