Metals Flashcards
refers to the group of materials that are used in the construction of manmade structures and components
Engineering Materials
refers to the group of materials that are used in the construction of manmade structures and components
Engineering Materials
Classification of Engineering Materials
Metallic
Non-metallic
Newborn engineering materials
Classification of Engineering Materials
Metallic
Non-metallic
Newborn engineering materials
__________ are usually lustrous, ductile, malleable and good conductors of electricity.
Metallic
two classified Metallic Material
Ferrous and Non-ferrous
Example of Metallic
Silver
Copper
Gold
Aluminum
zinc
lead
tin
Example of Metallic
Silver
Copper
Gold
Aluminum
zinc
lead
tin
refers to those materials whose main constituent is iron.
Ferrous
melting points of iron
1540°c
melting points of iron
1540°c
is an alloy of iron and carbon, the percentage of carbon theoretically varies from 0-2%
Steel
Classification of Steel
Plain Carbon and alloy
________________ is that steel which the only alloying element present is carbon
Plain Carbon Steel
________________ is that steel which the only alloying element present is carbon
Plain Carbon Steel
low carbon or dead mild steel having carbon below ________
0.15
mild steel having carbon between __________
0.15-0.3%
medium carbon steel having carbon between _________
0.3-0.7%
High carbon steels having carbon content above _______
0.7% ( the higher practical limit of C% IS 1.3%)
It has got very good weldability and ductility.
Dead mild steel
It is used very extensively for structural work.
Mild steel
It has little weldability but is stronger and has better wearing property the mild steel.
Medium carbon steel
It is used for hand tools like cold working dies, hammer, boiler maker’s tool, wood working tools, hand taps and reamers, filters, razors, shear blades etc.
High carbon steels
It is the purest form of iron
Wrought Iron
contain more the 2% carbon, which is the theoretical limit for steels.
Cast irons
Varieties of Cast Iron
Grey cast iron
White cast iron
Malleable cast iron
Nodular cast iron
Alloy cast iron
is very widely used in the forms of casting.
Grey cast iron
iron has 2 to 2.5% carbon and most of it is in the form of cementite.
White cast iron
starts out as white casting but is the threated at a heat of roughly 1,650 F, 900 C.
Malleable iron
is also called ductile iron, spheroidal graphite iron, and spheroidal graphite cast iron, is graphite-rich cast iron.
Nodular cast iron
have higher strength, heat-resistance and greater wear-resistance etc.
Alloy cast iron
what are the 3 groups of steels?
stainless steels
tool steel
special steels
These steels are called stainless because they do not corrode or rust easily.
Stainless Steel
Stainless steels are further divided into the following three categories
Ferritic
Martensitic
Austenitic
These steels contain a maximum of 0.15% carbon, 6-12% chromium, 0.5% nickel besides iron and usual amounts of manganese and silicon.
Ferritic Stainless Steel
These stainless have 12-18% chromium but contain higher carbon percentage (0.15-1.2%).
Martensitic Stainless Steel
These are the most important and costliest among all stainless steels.
Austenitic Stainless Steel
refers to different types of strong carbon and alloy steels that are especially suitable for making tools like reamers, drills, machine dies, and hand tools since they are very hard, resistant to wearing down and deformation, and can keep a sharp edge even when subjected to elevated temperatures.
Tool Steel
They are used for railway points and crossings, and with usage they become more wear-resistant.
Manganese Steels
makes the steel highly resistant to corrosion, non-magnetic, and having very low coefficient of thermal expansion.
Nickel Steels
makes steel corrosion resistant and increases its UTS.
Chromium
A steel containing 0.05% carbon, about 0.3% Mn and 3.4% of silicon possesses extremely low magnetic hysteresis and is used widely for making laminations of electrical machines.
Silicon Steels.
Kinds of heat treatment given to carbon steels
Annealing
Normalizing
Hardening
Tempering
is a heat treatment process that is used to make more ductile and tough after it has been subjected to thermal or mechanical hardening processes.
Normalizing
The purpose of ________________ is to soften the material.
Annealing
involves heating and soaking.
Hardening
means giving up a certain amount of hardness but shedding a great deal of brittleness acquired in the process of hardening.
Tempering
Only those carbon steels can be hardened whose carbon content is about 0.25% or more.
Case Hardening
They are softer and there more malleable.
Non-Ferrous Metals and Alloy
is a corrosion resistant metal of an attractive reddish brown color.
Copper
is a difficult to extract from its main called bauxite.
Aluminum
It has an attractive silvery white color.
Tin
is a heavy metal with dull grey appearance.
Lead
possesses a bluish grey metallic appearance,
Zinc
is a alloy of copper and zinc
Brass
is an alloy of copper and tin although commercial bronzes may contain other elements besides tin.
Bronzes
Give the Varieties of tin bronzes that are commonly used
Phosphor-Bronze
Leaded-Bronze
Gun-metal
Bell-metal
Addition of 0.5% phosphorous to tin bronze results in production of phosphorous bronze.
Phosphor-Bronze
is actually a source of weakness but adds to machinability and has self lubrication properties.
Leaded-Bronze
This bronze is used for bearing bushes glands, pumps, valves etc.
Gun-metal
Type of bronze contain no tin. It possesses good strength and good corrosion resistance. Color: golden yellow. Often used for jewelry. Composition: 14%
Aluminum Bronze
It is a tin bronze but having a very high percentage of tin (20-25%). It gives a good tinkling sound on being struck with a hammer.
Bell-metal
Type of bronze contain no tin. Possesses extremely good corrosion resistance. Can be cold worked and strain-hardened. Used for boiler fitting and marine fittings. Composition: 1-4%
Silicon Bronze
Type of bronze contain no tin. It is essentially a brass which manganese has been added. It is used for ship’s propellers. Composition: 40%
Manganese Bronze
Type of bronze contain no tin that very costly. It contains about 2% Be. It has very good mechanical properties and can be cold worked and age-hardened. It is mainly used for bellows, bourdon gauge tubes etc.
Beryllium Bronze
They are extensively used for marine fittings. They also possess good strength, hardness and ductility.
Cupro-nickels
It is a cupro-nickel to which zinc has been added.
German silver
Its composition is 68% nickel, 30% copper, 1% iron, remainder manganese etc.
Monel metal
Alloys principally containing, chromium and iron. Used in electrical industry.
Inconel and incoloy
Alloy of nickel and chromium, which is used as heat resistant electrical wire in furnaces and heating devices like geysers, electric iron etc.
Nichrome