METALS Flashcards
- is a soft , nonmagnetic silvery metal
- characterized by its light weight
- low melting point
- high thermal and electrical conductivity (surpassed only by silver and copper)
- moderately high coefficient of expansion
ALUMINUM
- is easily worked: can be hot or cold rolled, extruded, forged, pressed, drawn, molded, stamped, bent and shaped.
- can be riveted, bolted, welded, brazed and soldered
ALUMINUM
In architectural work practically all fabricated forms of aluminum are used
-rod
- bar
- extrusion
- casting
- sheet
- strip, etc.
Is the process of shaping
material by forcing it to
flow through a shaped
opening in a die.
EXTRUSION
(Extrusion)
these products are not fabricated from pure aluminum but in alloy combination with _________________(8) in small quantities to give strength and other desirable characteristics but often reduces its corrosion resistance.
iron, silicon, copper, manganese, magnesium, zinc, chromium and nickel
is a term applied to
certain aluminum products,
refers to the protective coating
(cladding) applied, primarily for
corrosion resistance, to thin
sheets of an alloy whose
corrosion resistance has been
decreased by the constituents
added to give strength and
other characteristics.
Alclad
_________ improves the appearance of the alloy. This thin, integral cladding usually consists of pure aluminum, magnesium silicide, or zinc alloys, with or without manganese.
Cladding
used for roofing,
flashing, gutter, etc
ALUMINUM SHEET AND
STRIP
rolled to a thickness of 0.005” , used mainly for thermal insulation and vapor barriers. It may serve also as a surface finish material when laminated to various sheet and board materials. In this form it also supplies additional insulation value
to the sheet or board.
ALUMINUM FOIL
This is rigidized sheet fabricated of special aluminum alloys specifically developed for this purpose. It usually consists of an aluminum alloy core of one type clad with another, highly corrosion-resistant aluminum roofing and siding
CORRUGATED ALUMINUM
.
When aluminum is used as a
structural material, important
factors, arising from its physical
and chemical characteristics,
are considered:
- Aluminum can be extruded;
- Very corrosion resistant aluminum alloys are
available;
____________ is very lightweight material, hence aluminum girders and columns show increased efficiency with large bay spacing. However, because the modulus of elasticity of aluminum alloys is lower than steel, its means that buckling is a possibility and should always be checked.
STRUCTURAL ALUMINUM
These are generally fabricated from extrusions and rolled shapes
ALUMINUM DOORS AND WINDOWS.
are pre-fabricated units, generally manufactured:- using dimensions of modular and non-modular window-width for building exterior, and- in 600mm, 900mm, and 1200mm widths for interior partitions and dividers.
ALUMINUM PANELS AND SANDWICH PANELS
A sandwich panel comprises a system of construction called ___________
A cellular core of aluminum or other material has
a skin of aluminum applied and bonded to both
sides, thereby forming a unified whole in which all
the components work as one.
skin construction
Many kinds of rods, bars, pipes, railings, fittings, and special shapes are manufactured as stock items for use in ornamental design of railings, grilles, screens, etc.
Ornamental aluminum
are used for fencing, particularly chain link fencing and insect screening.
Aluminum mesh and wire cloth
obtained by grinding polishing, scratching, sandblasting, embossing, or other treatment of the surface to achieve a desired effect or to provide a base for other finishes.
Mechanical finishes
based on chemical reactions
with the aluminum surface to achieve one of the
following results:
(a) etching, cleaning, or polishing
(b) oxidizing the surface with aluminum or other
metallic oxides
Chemical finishes
(chemical finish)
____________of the surface to remove any oxide film or surface irregularity and provide a design, a clean surface texture, or a polished effect;
etching, cleaning, or polishing
(chemical finish)
oxidizing the surface with ____________________ that protect the surface or serve as a base for subsequent treatment, or both. Chemical finishes permit only limited colors that are not as satisfying as the color films obtained on
electrolytically-applied (anodized) oxide films
aluminum or other metallic oxides
Commonly referred to as anodized finishes, these finishes are based on the specific ability of aluminum to develop a protective coating of oxide on its surface. The coating formed may be transparent or opaque.
. It is hard, yet when colored finishes are
desired, it is porous enough to absorb dyes until
the final treatment which seals the surface.
Of the colors used in anodic treatments, architectural gold has proven to be one of the most stable from the standpoint of fade resistance. Others are blue and, more recently, brown and black
Electrolytic finishes
Types of aluminum:
- ALUMINUM SHEET AND STRIP
- ALUMINUM FOIL
- CORRUGATED ALUMINUM
- STRUCTURAL ALUMINUM
- ALUMINUM DOORS AND WINDOWS
6.ALUMINUM PANELS AND SANDWICH PANELS
7.Ornamental aluminum - ALUMINUM MESH AND WIRE CLOTH
Aluminum can be covered with a protective or decorative film or another metal,
usually by electrodeposition. In the case of
copper and nickel, the coating should be
complete and unbroken; otherwise there will be
galvanic action which is destructive to aluminum
Electroplating
This finish forms a hard, resistant surface. It is available in a broad color range that creates a different feeling in that colors are glassy, whereas anodic color is metallic in nature
Porcelain or Vitreous Enamel
________ can be applied as finishes to aluminum surfaces that have been prepared by a suitable chemical treatment finish. Lead based _____ must not be used on aluminum.
Paint
TYPES OF ALUMINUM FINISHES:
Mechanical finishes
Chemical finishes
Electrolytic finishes
Electroplating
Porcelain or Vitreous Enamel
Paint
- tough, malleable silvery-white metal that is soft and ductile as copper
- it is easily magnetized
- is the most magnetically permeable of the metals
- it oxidizes rapidly in air and is readily attacked by most acids.
- can be hardened by heating and sudden cooling
- and made more pliable or more workable by heating and slow cooling.
- At very low temperatures is very brittle
- at red heat it is soft, and
- at white heat it can be welded.
IRON
The commercial form in which iron is first prepared is _____________.
This impure form which contains 3% to
4% carbon and varying amount of phosphorous, silicon, sulfur, and manganese, is the starting point from which all other kinds of iron and iron alloys (or steel) are produced.
crude or pig iron
The key to the various types of iron and steel is the
carbon-iron relationship.
- is an iron-carbon alloy that contains more than
1.7% carbon - is poured while molten into forms
- it can be easily cast into any shape, but it is too hard and brittle to be shaped by hammering, rolling, or pressing.
Cast Iron
is used in the architectural field mainly for piping and fittings, ornamental ironwork, hardware, as the base metal for porcelain enameled plumbing fixtures, and for miscellaneous casting such as floor and wall brackets for railings, vents, circular stairs manhole covers, and gratings.
Cast Iron
________ find their largest use in heavy machinery and industry because it has significant compressive strength and the ability to absorb energy and stop vibration
Cast irons
- is soft, malleable, tough, fatigue
resistant, and resistant to progressive corrosion. - It has good machinability and can be forged, bent, rolled, drawn, and spun. It can be welded by any of the commonly used procedures. It is available in the form of pipes, plates, sheets, special shapes, and bars.
Wrought Iron:
________ is now used in the architectural field primarily in the form of genuine ________ pipe, chain, sheet, and ornamental ironwork.
_________ pipe is used extensively for plumbing, heating, and air conditioning where a corrosion-resistant, tough, durable material is required. Because it is intrinsically related to classical architecture and requires high skilled craftsmanship, this work today is used only in furniture, railing, fences, grilles, and small decorative objects
Wrought iron
The word “________” refers usually to plain carbon steels which is defined as alloys of iron and carbon which do not contain more than 2% carbon and which are made in malleable or ingot form.
steel
________ can be wrought, rolled, cast, and welded, but not extruded.
Carbon steel
This is a medium carbon steel with its carbon content controlled to give both the strength and ductility necessary for its use.
________ is available in angles,
channels, I-beams, H columns, T shapes, Z shapes, plates, round pipe columns, sheet piling, open web joists, and light steel framing shapes.
Structural steel
Usually deformed bars of varying grades and diameters
Reinforcement of concrete
________ Is made from low carbon steels generally containing about 0.15% carbon and not exceeding 0.25% carbon.
________ by definition is sheet material that is 12” or less wide. It is used in fabricated form as decking galvanized sheet, expanded metal, panels and sandwich panels, and as a base metal for porcelain enamel
Sheet and strip
This is rigidized sheet fabricated from low-carbon cold or hot-rolled steel sheets which are either galvanized or covered with some type of bituminous coating. If galvanized, corrugated steel is silvery in color and has a glittering frosted surface. It is generally available in 18, 20, 22. 24, and 26 gauge sheet and strip.
Corrugated steel.
They are used for concrete reinforcement, lath for plaster, stucco, and cement, fencing, insect screens
Steel Mesh and Wire Cloth.
Wrought Carbon Steels:
________ such as nails, screws, rivets, etc
Hardware
steels to which manganese, silicon, aluminum, titanium, and molybdenum have been added in sufficient quantity to produce properties unobtainable in carbon steels in cast, rolled or heat-treated form.
Alloy Steels
____________are a group of trade name steels with improved mechanical properties and resistance to atmospheric corrosion, They are being increasingly used as reinforcing for pre-stressed concrete, high strength bolts, special structural steels and cables for elevators, etc
High-strength low-alloy steels
generally used in architecture are highly alloyed steels that contain more than 10%
chromium. They are characterized by their resistance to heat, oxidation and corrosion. They are used where corrosion resistance, durability, and minimum of maintenance is necessary principally for exterior and interior wall finishes, doors, windows, trims, railings, signs and letters, appliances, etc.
Stainless steels
is ductile, malleable, nonmagnetic metal with a characteristic bright, reddish brown color.
* is useful alloys have enough strength for
minor structural work
* easily worked.
* It is attacked by alkalis and many of the common
acids.
COPPER
- is one of the best electrical conductors, it has the highest electrical and thermal conductivity of any substances except silver.
- It is highly resistant to corrosion by air and salt water.
COPPER
On exposure it soon reacts to form a surface layer of an insoluble green salt which retards further corrosion; this green color on copper is known as its _________.
patina
is a soft, ductile, malleable, bluish-white metal.
* Because it is normally covered with a thin film of
stannic oxide, it resists corrosion by air, moisture, sulfur dioxide, hydrogen sulfide (which usually tarnishes and corrodes other metals).
* takes a highly reflective polish and has the ability to wet other metals.
TIN
The main use of ____ is for protective coatings on stronger metals
tin
Architectural uses of tin include:
bronzes, brasses, terneplate, mirrors, gilding, solders, hardware and fusible alloys.
- is medium hard, bluish-white metal
- is characterized by brittleness and low strength.
- is readily attacked by acids and alkalis.
- It is resistant to corrosion by water. On exposure to
air, a film of zinc carbonate or oxide forms which protects zinc from further oxidation.
zinc
The most important uses of zinc are
as protective coatings (galvanizing) on iron and steel
as die-casting metal, and
as an alloying element in brasses.
________ is the process whereby a protective coat of zinc is applied to steel and iron to protect them against corrosion.
The advantage of coating them with zinc is that, should the iron or steel become exposed through wear, aging or discontinuities, galvanic reaction between the coating and the base metal causes the zinc to corrode and form compounds which cover and remain continue to protect the iron and steel for as long as any zinc remains.
Galvanizing
The most common
galvanized material used in
architecture is
galvanized iron (steel) sheet and strip
________ become defaced and discolored
when subjected to dampness and extremes of temperature.
if the sheets are piled flat in the open or tightly
bundled in a warehouse, the zinc coating can also be
damaged by the consequent absence of oxygen and
carbon dioxide between two sheets. This absence
prevents the formation of a protective film of zinc
carbonate; instead zinc hydroxide forms and destroys the galvanizing
Galvanized sheets
________ fundamentally an alloy of copper and zinc with small quantities of other elements sometimes added to give the special qualities.
* The copper-zinc proportions may vary from 95%
copper and 5% zinc to 55% copper and 45% zinc.
* As a class, these alloys are less hard and strong
than steels (iron-base alloys) but are superior in workability and resistance to corrosion.
BRASS
- In architecture, ____ are used for doors,
windows, door and window frames, and for
ornamental metalwork such as railings, trims,
grilles, etc. - They are also used extensively for finish hardware, plating of hardware, and other miscellaneous accessories such as** screws, nuts and bolts, anchors, etc**
brasses
____is a rich golden-brown metal, originally worked by forging and particularly suited for casting since it is corrosion resistant, dense and hard enough to take an impression of a mold of any delicacy whatever
bronze
True bronze is an ____________ which varies only slightly from 90% copper and 10% tin composition.
alloy of copper and tin
The architectural uses of ________ are confined to statuary, plaques, medallions and other ornamentation, and miscellaneous rough and finish hardware.
bronze
is a steel-white metal which takes a brilliant polish and is harder than cobalt or nickel.
* It is nonmagnetic at ordinary temperatures but becomes magnetic at 13F.
* It does not tarnish in air, resists oxidizing agents, is
soluble in acids and strong alkalis
CHROMIUM
The principal use of chromium is an
alloying ingredient in ferrous and nonferrous metallurgy.
____________ is one of the most
commonly encountered usage of this material in architecture. It gives a thin, hard, bright, wear resistant surface which sheds water when highly polished. The metals that can be plated
with chromium include aluminum, copper, iron,
magnesium, nickel, titanium, zinc and their alloys. The chromium is electro deposited as a thin layer of pure metal.
Chromium plating
is an inert silvery metal
* is resistant to strong alkalis and to most acids.
* It resembles iron in strength and toughness and copper in its resistance to oxidation and corrosion.
* it takes a high polish and can be hot and cold
rolled forged, bent, extruded, spun, punched
and drawn.
NICKEL
When alloyed with other metals, nickel imparts its
qualities of strength, hardness, toughness, ductility, corrosion resistance, and strength at high
temperatures to the resulting material. The major
use of nickel therefore is in ______ .
alloys
Another important use of nickel is as ________ for other metals. It can be applied to the following base metals and their alloys: aluminum, brass, copper, iron, magnesium, steel, tin, and zinc
protective or
decorative coating
is a blue-gray, soft, very heavy metal (the heaviest of the common metals).
It is extremely workable, has good corrosion resistance, is easily recovered from scrap materials, and is relatively impenetrable to radiation. The corrosion resistance of lead arises from the fact that metallic lead does not react with many compounds or solutions, and with certain others it forms
compounds which act as protective coatings against further corrosion
LEAD
________ also finds many uses in rough hardware items such as expansion shields for securing bolts, screws, and other accessories in masonry, washers, lead-headed nails,etc.
Lead
is a method to join metals, to
make electrical connections, to seal joints hermetically with another lower melting metal
or alloy called the solder.
SOLDERING
Solders are mostly alloys of tin and lead in various proportions with small percentages of other elements added to give special characteristics. They can be divided into the following major types (3)
- tin-lead
- tin-lead-antimony
- silver-lead.
Some tin-lead are used for coating the metals before soldering. This is known as ________
pre-tinning.
defined as a metaljoining process where the workpieces to be joined are immersed in a
pot of molten solder.
Because of the relatively low melting temperature of
the solder (between 350 and 600 degrees F), only
adhesion between the solder and the workpieces
results. A flux or metal cleaner is used to prepare the workpiece for bonding with the solder
Metal Bath Dip
In this method the iron piece is preheated and
applied to the joint along with the solder and the flux (the flux is a substance used in soldering to clean the surfaces of the metals to be joined and to aid fluidity); the heat from the iron forms the
soldered joint
Soldering Iron
The parts to be soldered are heated by the torch flame and then the solder and flux are applied. This method is limited to metals which can be heated without altering their characteristics.
Torch
The heating of the metals to be joined causes the
solder to run into the joint. This is the method used
for joining copper tubing and fittings.
Sweat Method
is a typical neutral flux.
Stearic acid
________ is a type of soldering in which the operating temperatures are higher (but lower than in welding) and in which stronger and higher-melting alloys are used to fill the joints, which consequently are stronger than ordinary soldered joints. The bond is obtained by alloying between the brazing material and the surface of the joined metals
Brazing
________is generally used where the shape and position of the joint or the composition of the metal or metals are not adaptable to welding.
Brazing
Brazing materials fall into six major types: ________. Each type is particularly suited to a certain group of metals. The brazing materials are prepared by melting and mixing together the metallic ingredients to fixed and controlled proportions
aluminum-silicon,
copper-phosphorous, silver, copper, and copper-zinc,
magnesium, and heat-resistant alloys
________is the process by which two metals are so joined that there is an actual union of the interatomic bonds. This may be
brought about by close contact, heating, pressure, adding molten metal, or combinations of these methods. The resulting
joints are as strong or stronger than the metals joined.
Welding
Welding may be divided into two general types: _____________________________
pressure welding-in which pressure and heat make the weld; and
fusion welding- in which the heat and added metal make the weld.
________ are devices used to join or fasten the metals. A metal cylinder or rod which has a head at one end, is inserted through holes in the materials being joined, and then the protruding end is flattened to tie the two pieces of material together.
Rivets
Fluxes for soldering are generally of three types:
corrosive, neutral and noncorrosive.
Reinforcement for concrete construction is
mostly in the form of steel bars and rods of
round or square cross section. The bars may
be plain or deformed (with lugs or projections
for better bonding to the concrete). They are
called __________
billet-steel bars or rail-steel bars.
Billet-steel bars are made by the open hearth furnace by the acid Bessemer furnace and meet fixed chemical compositions. They are rolled from billets directly reduced from ingots and come in three grades: ___________.
structural, intermediate, and hard
________ made of cold-drawn steel wire is
widely used for the reinforcement of concrete
slabs and floors, as well as for stuccoed work.
Wire fabric
used to reinforce concrete slabs used in
light construction., consists of a series wires
welded together to form a grid pattern.
It comes in various sizes & spacings and gauges, e.g. 4” x 4” – 6/6, 6” x 6” –8/8, etc. The first pair of numbers refer to the spacing of the wires: the second pair refers to the gauge of the longitudinal and transverse wires respectively.
Welded-wire mesh, also
called welded-wire fabric
is built up of either single or stranded longitudinal wires with cross wires or bond-wires running diagonally across the fabric. The longitudinal wires are spaced at 4” on centers and the cross wires 4” or 8” apart.
Triangle-mesh Wire Fabric
This is manufactured from solid steel sheets. it is free from mechanical and welded joints., e.g. STEELCRETE
EXPANDED MESH
Metal reinforcement shall be stored in _________ from moisture and vegetation. If a large quantity of reinforcement is stored at the site for an extended period, it is well to build shed over the storage racks.
racks above the ground and away
All reinforcement should be kept free from ____ which will tend to reduce the bond between concrete and steel
Oil
The alloying elements are added to increase the following properties: (7)
✓ strength
✓ hardness
✓ ease and depth of hardenability
✓ performance at high or low temperatures
✓ electromagnetic properties
✓ wear resistance
✓ electrical conductivity or resistivity.
The alloying elements are added to increase the following properties, In structural applications only the properties of:
________(5)
are of interest to the architect.
✓ strength
✓ expansion
✓ resistance to corrosion
✓ ductility, and
✓ workability
