105 Flashcards
A metal’s ability to be stretched into wire without breaking is called its ____. Its ability to return to its original shape after being deformed is called its
Ductilty, elasticity
Which of the following magnetic materials is an alloy?
Alnico
A solid and a liquid can exist together at the _____. Adding heat melts more of the solid ______ changing the temperature.
Melting point; without
An alloy containing iron as the base metal is
Steel
Machinability is the speed and ease with which a metal
Can be cut on a machine tool
Lead and tin are alloyed in various proportions to make
Solder
Lead wool can be used to
Form cold welded seals
Which nickel alloy is commonly used for making the heating elements in toasters? (^®Invar and Monel are trade names of the International Nickel Co.)
Nichrome^
Galvanizing is the process of coating sheet steel with
Zinc
Which of the following should you use as a lubricant when machining zinc?
Lard oil
The maximum amount of stress a material can exert is called its
Yield strength
A standard tensile test specimen exerts a resistance force of 8500 lb. What is the stress in the specimen?
42,500 psi
When a metal supports a heavy load at high temperature, it may undergo
Creep
The mass of a material per unit volume is called its
Density
The ratio of a material’s density to the density of water is called its
Specific gravity
Permanent-mold casting uses
Both metal and sand cores
The method of casting metal parts using a spinning mold to force the molten metal away from the center and against the sides of the mold is called ______ casting
Centrifugal
Die casting is the ______ of all casting methods. It is used to cast ______ metals
Fastest, nonferrous
Upsetting is the most common method of
Cold forging
Pulling rod stock through a tapered die produces
Wire
Because of its higher carbon content, ______ has a lower melting point than _______.
cast iron, steel
Carbon in cast iron generally makes the metal easier to
Break
Malleable cast iron is ____ than white cast iron and has _____ resistance to wear than gray cast iron.
softer, more
What kind of cast iron is best for parts that must be hard and strong but not brittle?
High-alloy
Open-hearth, basic oxygen, and electric are three types of fumaces used for making
Steel
The most important element added to iron in making steel is
Carbon
AISI and SAE are number coding systems that specify the _____ of each kind of ____.
Chemical composition, steel
When spark testing to identify a steel, you should consider spark length, _______, and ________.
Color, burst
The cold-rolled sheet steel graded ______ quality has a matte finish that holds paint well.
Commercial
All stainless steels contain
Chromium
Uneven heating and cooling of metal parts during welding causes
Distortion
In annealing, a metal should be heated to a temperature above its critical temperature, and then
cooled slowly
Before welding a broken gear, you should ________ it in order to avold distortion.
Preheat
Steels that are _____ generally have a ______ -carbon content.
Forged, low
High-carbon steels contain ______ percent carbon.
0.55 to 1.00
Copper alloys are made harder by
Cold-working
Copper alloys that contain lead are relatively ______ to _______
Easy, machine
What copper alloy contains 36% to 50% zinc?
Beta brass
Muntz metal is the strongest
Brass
What copper alloy is most widely used for casting?
Ounce metal
The process of rolling a thin layer of aluminum onto a base metal is called
Cladding
What causes aluminum to lose its strength during welding?
Increased temperature
Intermediate-temperature solders melt and flow at temperatures of ____ to _____° F
500, 700
When aluminum is exposed to the air, a layer of ____ forms on the surface
Oxide
In the four-digit aluminum designation number 6053, which digit signifies the main alloying element?
6
The two methods of extracting magnesium from brines and ores are _____ and ______
Electrolysis, reduction
Which magnesium casting alloys have the lowest yeld strength at high temperatures?
AZ
The letter “a” following the designation for a rolled sheet of magnesium stands for
Annealed
Magnesium parts should be gas welded
Only in emergencies
Typical melting and casting methods cannot be used for ______. It can be arc melted using _____ gas
Titanium, argon
