Chapter 7 metals Flashcards Preview

CTech > Chapter 7 metals > Flashcards

Flashcards in Chapter 7 metals Deck (30):
1

Decorative Metals

Include a wide variety of functional and decorative products, including handrails, guardrails, elevator interiors, custom doors, custom light fixtures, and many other building components
-Most commonly used metals are stainless steel, copper alloys (bronze, brass), and aluminum
-Steel, copper, iron, zinc also sometimes used

2

Stainless Steel

Steel alloy containing 12% or more chromium; may also contain nickel, manganese, molybdenum
Highly corrosion resistant, very strong
Available in sheet, plate, strip, bar, angles, channels, tees, and solid shapes. Pipe and tubing also available

3

Pipe vs. Tubing measurement

Pipe: measured by I.D.
Tubing: measured by O.D.

4

Stainless Finishes

Rolled, polished, etched most common

5

Detailing Stainless Steel

-Similar to carbon steel, can be welded, mechanically fastened, sometimes bonded with adhesives
-Fasteners should also be stainless steel to prevent galvanic action

6

3 main types of Copper alloys

-Almost pure copper
-‘architectural bronze’ or common brasses
-Nickel-silver/silicon bronze alloys

7

Welding

joins two metals by using high temperatures to heat them above their melting points either with or without a filler metal

8

Brass

-Brass is alloy of copper and zinc
-Standard shapes similar to stainless steel available
-Brass is often finished using chemical finishes that alter the surface
-Coatings are applied finishes formed from metal itself

9

Anodic (Anodized) finish

electrochemical process that forms an oxide coating on the metal surface when placed in a bath of chemicals with an electric current

10

Monel Metal

-Nickel-copper alloy, silver-gray color slightly grayer than stainless steel
-Very expensive, highly corrosion-resistant

11

Zinc

-In architectural applications, traces of copper & titanium added to reduce brittleness
-Uniform gray color, can be embossed, hammered, polished, engraved, colored

12

Steel

-Usually used where appearance not a concern; very strong, must be coated/painted where corrosion resistance is required
-Fastened mechanically, using adhesives, and welding

13

Iron

Cast and wrought iron two main types; cast has 1.7% carbon, Wrought has .03-.05%

14

Bronze

- Technically, bronze is an alloy of copper and 2% or more of tin
-Much of what is called bronze in general use is actually a brass alloy
-None of the common alloys used in architectural interiors are true bronzes

15

Brass Fastening

-Brass can be welded, but is normally brazed, soldered, mechanically fastened, and installed with adhesives
-Brazing joins metals at intermediate temperature (800F) using nonferrous fillers
-Soldering uses lead/tin based filler, lower temperature (500F)
-Welding joins metals by melting together at much higher temperatures

16

Aluminum

-Components usually extruded
-Can be made in a wide array of shapes
-Finished using mechanical, chemical, and anodic processes (anodizing)-electrochemical process that forms an oxide coating on metal surfaces
-Fastened mechanically, using adhesives, and welding (usually TIG)

17

Perforated Metal

-Sheet metal punched with regular pattern of holes
-Standard perforations include round, square, and slotted holes
-Used as space dividers, railing guards, shelving, furniture, air grilles, light fixtures
-Steel, stainless steel, aluminum commonly available; verify standard available sizes during design process to keep cost, waste to a minimum
-Note margins, finished edges, staggered vs. straight hole patterns have different appearances

18

Galvanic Series of Metal

-When different metals come into contact, electrical current flows between them, and corrosion of the more active or anodic metal results.
-Avoid direct contact between metals far apart on the galvanic series. The further apart the metals on the list, the greater the electrical potential difference and the greater the potential corrosion. For example, it is relatively safe to have copper and tin in direct contact; but contact between copper and zinc should be avoided
-It is usually safe for fasteners to be more cathodic than the metals they attach. For example, stainless steel fasteners are OK for copper sheet; zinc coated fasteners are not

19

Unified Numbering System (UNS)

used to designate all commercial metals and alloys
- letter prefix to designate general type of metal then followed by a five-digit number that identifies the specific alloy

20

Mechanical finish

alters the surface of the metal by rolling or some other mechanical means

21

Chemical Finishing

alters the surface with chemical processes

22

Coated Finishes

are applied finishes that are formed from the metal itself through chemical or electrochemical conversion or by adding some other materials.

23

Methods of Fastening

joined with mechanical fasteners or adhesives, or by brazing or soldering

24

Mechanical Fasteners

- includes screws bolts, rivets, and various types of clips compatible alloys

25

Brazing

is the joining of two metals at an intermediate temperature above 800 degrees Fahrenheit using a nonferrous filler metal

26

Soldering

joining of two metals using lead-based or tin based alloy solder that melts below 500 degrees Fahrenheit

27

Mechanical Finishes of Aluminum

includes buffed, directional- textured, non-directional textured and patterned

28

Wrought Iron and Cast Iron work

produced by forging, casting, stamping, and hammering to produce custom construction elements

29

Iron is joined......

joined by forge welding, riveting, collaring, and wrapping

30

anodizing

electrochemical process that forms an oxide coating on metal surfaces