Diploma Strength of Materials N Scheme Study Materials Unit – 1 Part 1

Diploma Strength of Materials N Scheme Study Materials Unit – 1

Strength Of Materials

Unit – 1 

Chapter: 1.1: Engineering materials: Classification – definition of Mechanical properties – ferrous metals – cast iron – uses – advantages – types of cast iron – properties and applications – effect of impurities on cast iron. steel – classification – alloying elements – purpose of alloying – effect of alloying elements on steel – uses of steels – properties of mild steel – defects in steel – applications – properties of hard steel – market forms of steels – nonferrous metals – properties and uses.

Three Marks

Mechanical Properties ( three marks / 14 marks)

  1. Strength

  • Strength is the mechanical property that enables a metal to resist deformation load.
  • The strength of a material is its capacity to withstand destruction under the action of external loads.
  • The stronger the materials the greater the load it can withstand.

2. Elasticity

  • According to dictionary elasticity is the ability of an object or material to resume its normal shape after being stretched or compressed.
  • When a material has a load applied to it, the load causes the material to deform.
  • The elasticity of a material is its power of coming back to its original position after deformation when the stress or load is released.
  • Heat-treated springs, rubber etc are good examples of elastic materials.

3. Plasticity

  • The plasticity of a material is its ability to undergo some permanent deformation without rupture(brittle).
  • Plastic deformation will take place only after the elastic range has been exceeded.
  • Pieces of evidence of plastic action in structural materials are called yield, plastic flow and creep.
  • Materials such as clay, lead etc are plastic at room temperature, and steel plastic when at bright red-heat.

4. Hardness

  • The resistance of a material to force penetration or bending is hardness.
  • The hardness is the ability of a material to resist scratching, abrasion, cutting or penetration.
  • Hardness indicates the degree of hardness of a material that can be imparted particularly steel by the process of hardening.
  • It determines the depth and distribution of hardness is introduce by the quenching process.
  1. Toughness

  • It is the property of a material which enables it to withstand shock or impact.
  • Toughness is the opposite condition of brittleness.
  • The toughness is may be considering the combination of strength and plasticity.
  • Manganese steel, wrought iron, mild steel etc are examples of toughness materials.

6. Brittleness

  • The brittleness of a property of a material which enables it to withstand permanent deformation.
  • Cast iron, glass are examples of brittle materials.
  • They will break rather than bend under shock or impact.
  • Generally, the brittle metals have high compressive strength but low in tensile strength.
  1. Stiffness

  • It is a mechanical property.
  • The stiffness is the resistance of a material to elastic deformation or deflection.
  • In stiffness, a material which suffers light deformation under load has a high degree of stiffness.
  • The stiffness of a structure is important in many engineering applications, so the modulus of elasticity is often one of the primary properties when selecting a material.
  • Diploma Strength of materials N Scheme important questions, Diploma N scheme Strength of materials Important Questions, N Scheme Strength of materials important question, Diploma N scheme Mechanical important questions

8. Ductility

  • The ductility is a property of a material which enables it to be drawn out into a thin wire.
  • Mild steel, copper, aluminium are the good examples of a ductile material.

9. Malleability

  • The malleability is a property of a material which permits it to be hammered or rolled into sheets of other sizes and shapes.
  • Aluminium, copper, tin, lead etc are examples of malleable metals.
  1. Impact Strength

  • The impact strength is the ability of a metal to resist suddenly applied loads
  1. Fatigue

  • The fatigue is the long effect of repeated straining action which causes the strain or break of the material.
  • It is the term ‘fatigue’ use to describe the fatigue of material under repeatedly applied forces.
  1. Creep

  • The creep is a slow and progressive deformation of a material with time at a constant force.
  • The simplest type of creep deformation is viscous flow.
  • Some metals are generally exhibiting creep at high temperature, whereas plastic, rubber, and similar amorphous material are very temperature sensitive to creep.
  • The force for a specified rate of strain at constant temperature is called creep strength
  1. Resilience

  • Resilience is the property of a material to absorb energy and to resist shock and impact loads

 

  1. Castability

  • Castabilty is the property of metal by which it is easily formed into different complex shapes and sizes from its molten state
  1. Weldability

  • Weldability is the property of a metal which easily joined by fusion with or without applying pressure
  1. Wear Resistance

  • Wear resistance is the property of a metal which enables it to resist wear where there is relative motion between that metal and adjacent machine parts
  1. What is Ferrous metals?
  • Ferrous metal are those which heva iron as their main constituent
  • The commonly used ferrous metals are cast iron, wrought iron & alloy steels
  1. What is Cast Iron?
  • Cast Iron is an alloy of Iron and Carbon
  • Cast Iron usually contains 2.5 – 3.5 % carbon and varying amount of silicon,manganese, phosphorous and sulphur
  1. What are the applications of Cast Iron?

Cast Iron is used in

  • Making pipes to carry fluid
  • Making automotive parts
  • Making pipes
  1. What is Steel?

Steel is an alloy of Iron and carbon contents upto 1.5% and other than carbon, sulphur, silicon, phosphorus, manganese is also present in steel

  1. What is the purpose of Alloying?
  • The purpose of alloying is to increase hardness, toughness, strength, ductility, machinability & Weldability
  • The purpose of alloying is to improve wear resistance, corrosion resistance, physical and electrical properties of the alloy
  1. What are the uses of alloy steels?

Alloy Steels are commonly used in forged products, Rolled products & sheet mill products

  1. What are the applications of aluminium?

Aluminium is used for power transmission in over head wires, cooking appliance, aircraft and automobile components

Join Diploma Exam Corner

Study Materials 

WhatsApp Group 

Click here
Job Alert

WhatsApp Group

Click here
Telegram Channel Click here
YouTube Click here
English Version Click here
TNPSC Free test Click here
Powered by Diploma Exam Corner

 

Leave a Comment

Ads Blocker Image Powered by Code Help Pro

Ads Blocker Detected!!!

We have detected that you are using extensions to block ads. Please support us by disabling these ads blocker.

error: Content is protected !!