Welcome to AMIE Study - AMIE India Students Forum

AMIE Study - AMIE India Students Forum

collapse collapse

* Shoutbox

Refresh History
  • bharath kumarrs: I am nt getting online registration for section B
    February 21, 2019, 09:44:00 PM
  • Amal Babu: Is there any changes in syllabus
    February 12, 2019, 06:17:52 PM
  • bhoomika Praveena: any whatsapp group? kindly add me ,mail me to [email protected] your number i shall ping you thanks
    February 01, 2019, 07:36:26 PM
  • bhoomika Praveena: hi,
    February 01, 2019, 07:33:15 PM
  • Sitigaurav: Section A note required
    January 13, 2019, 03:12:13 PM
  • Ulo3091: Please send doc file of project report someone
    December 29, 2018, 05:36:05 PM
  • Sujith Raj (AMIE - Civil): Any Idea, When will we get AMIE certificate & AM number
    December 20, 2018, 04:30:22 PM
  • Sujith Raj (AMIE - Civil): Congratulation to All those who cleared AMIE in recent result
    December 20, 2018, 04:29:40 PM
  • sulemangani: Can I reresisyered for section B exam as I have passed section A in winter 2008 but not appeared in some exams upto winter 2014
    December 12, 2018, 06:59:49 PM
  • I P Sarath Menon: Rcc , steel, advance structural analysis, design and analysis, soil, water hand written notes which was used to successfully complete AMIE [email protected]/9387774349
    November 28, 2018, 09:37:56 AM
  • I P Sarath Menon: Civil Engineering notes with optional structural with me
    November 28, 2018, 09:33:52 AM
  • ST694011-6: Hi everyone how to get RCC notes
    November 28, 2018, 09:17:25 AM
  • rekha1996: dbms
    November 27, 2018, 05:58:47 PM
  • rekha1996: Dbms
    November 27, 2018, 04:52:21 PM
  • Anwar VYM: Is AMIE degree acceptable in UAE?
    October 23, 2018, 10:16:46 PM
  • devjangde: Dear Sir/Madam please me out for my membership Number and  reference number.  I lost both of this . Is there any way to find out?
    October 08, 2018, 09:32:50 AM
  • devjangde: Dear Sir/Madam,
    October 08, 2018, 09:30:46 AM
  • Srijib: Can someone have any notes for the subject society and environment
    October 07, 2018, 07:37:52 PM
  • muleredd: can someone have previous year question papers for Sec B Mining Engineering ?
    October 07, 2018, 01:52:05 PM
  • Pahadi57: Will I send the printed copy of the winter application form after online form filling successfully.... Pls advice
    October 05, 2018, 05:54:03 PM

* Search


* User Info

 
 
Welcome, Guest. Please login or register.
Did you miss your activation email?

* Board Stats

  • stats Total Members: 48807
  • stats Total Posts: 27371
  • stats Total Topics: 6635
  • stats Total Categories: 6
  • stats Total Boards: 31
  • stats Most Online: 626

Author Topic: note for section A  (Read 588 times)

Description:
July 21, 2010, 05:01:08 PM
  • Super Member
  • Registered User
  • *
  • Posts: 34
    • View Profile
Advertisement
work hardening

Almost all ductile materials become stronger when they are deformed plastically. As a result its strength increases. This increase in strength is called strain hardening. it provides opportunities for the engineer to modify and control the properties of ductile materials, particularly metals.

Work hardening is also known as strain hardening. It is the strengthening of a metal by plastic deformation. This strengthening occurs because of dislocation movements within the crystal structure of the material.

Any material with a reasonably high melting point such as metals and alloys can be strengthened in this fashion. Alloys not amenable to heat treatment, including low-carbon still, are often work hardened. Some materials cannot be work hardened at normal ambient temperatures. Their names are given below:
 
•   Indium
•   Pure Copper
•   Aluminum

Examples of desirable and undesirable work hardening:

Generally speaking work hardening may be desirable or undesirable depending on the context.

•   An example of undesirable work hardening is during machining when early passes of a cutter inadvertently work harden the work piece surface, causing damage to the cutter during the later passes.

•   An example of desirable work hardening is that which occurs in metalworking processes that intentionally induce plastic deformation to exact a shape change. these processes are known as cold working or cold forming processes.

Disadvantage Of Work Hardening:

Although work hardening or strain hardening increases both the yield strength and the ultimate strength, it reduces the ductility. Part of the deformation occurred during cold working of the material, before the test bar was made and the gage marks established. Thus, less ductility is observed during testing. Cold working increases the yield strength more than it does the ultimate strength.



. Ductile Fracture

Ductile fracture is a mode of fracture that is attended by extensive gross plastic deformation.
The failure of many ductile materials can be attributed to cup and cone fracture. This form of ductile fracture occurs in stages that initiate after necking begins. the stages of ductile fracture are given below:
                                     

•   Small micro voids form in the interior of the material.
•   Deformation continues and the micro voids enlarge to form a crack.
•   The crack continues to grow and it spreads laterally towards the edges of the specimen.
•   Finally, crack propagation is rapid along a surface that makes about 45 degree angle with the tensile stress axis. The new fracture surface has a very irregular appearance. the final shearing of the specimen produces a cup type shape on one fracture surface and a cone shape on the adjacent connecting fracture surface, hence the name cup and cone fracture.

 

Basic Factors Of Brittle Fracture:

Three basic factors contribute to a brittle cleavage type of fracture. They are –

•   a tri-axial state of stress
•   a low temperature
•   a high strain rate or rapid rate of loading

The above mentioned factors do not have to be present at the same time to produce brittle fracture. a tri-axial state of stress, such as exists at a notch, and low temperature are responsible for most service failures of the brittle type. However, since these effects are accentuated at a high rat of loading, many types of impact tests have been used to determine the susceptibility of materials to brittle behavior. Steels which have identical properties when tested in tension or torsion at slow strain rates can show pronounced differences in their tendency of brittle fracture when tested in a notched impact test.
•   ductile fracture results from the application of an excessive force to a metal that has the ability of the material to flow or deform, which may or may not lead to fracture, depending upon the magnitude of the force applied.
•   The property of ductility is somewhat related to the property of toughness, although the latter is usually measured in the presence of a notch or other stress concentration. The chirpy v notch impact test is commonly used as a measure of toughness. However, the ability to absorb energy and deform plastically prior to fracture is characteristic of both ductility and toughness.
•   the property of ductility permits metal parts to be formed without fracture and to be adjusted in shape. a simple example is familiar to all persons who wear metal eyeglass.

Characteristics of Ductile Fracture:

1.   There is considerable gross permanent or plastic deformation in the region of ductile fracture. In many cases, this may be present only in the final rupture region of a fracture that may have originated with a fatigue or brittle   fracture.
2.   The surface of a ductile fracture is not necessarily related to the direction of the principal tensile stress, as it is in a brittle fracture.
3.   The characteristic appearance of the surface of a ductile fracture is dull and fibrous. this is caused by deformation on the fracture surface, which will be discussed in the section on the micro structural aspects of ductile fracture.

                  THESE NOTES ARE FOR EXAMPLE. I AM PREPARING THE MATERIAL IN THIS STYLE. M.9898679505
« Last Edit: January 01, 1970, 04:00:00 AM by Guest »


 

Related Topics

  Subject / Started by Replies Last post
0 Replies
387 Views
Last post July 25, 2010, 11:35:55 AM
by mrs poonam
2 Replies
549 Views
Last post September 17, 2010, 11:20:35 PM
by noni gopal
0 Replies
289 Views
Last post July 26, 2010, 04:38:12 PM
by mrs poonam
0 Replies
277 Views
Last post July 26, 2010, 04:38:43 PM
by mrs poonam
0 Replies
359 Views
Last post July 26, 2010, 04:39:34 PM
by mrs poonam
2 Replies
584 Views
Last post September 21, 2010, 06:56:09 PM
by kavitha suresh
0 Replies
808 Views
Last post December 09, 2010, 01:56:15 PM
by shitalbshinde

* Search

* Subscribe to Forum

Enter your email address:

Advertisement

* Recent Posts

Solid Wood Dining Table Set Uk by alvisys
[January 30, 2019, 04:58:57 PM]


Re: Important!!! AMIE Exam fee revised from Rs 2000 to Rs 3000 by JessicaThisk
[January 09, 2019, 06:30:22 PM]


Re: Important!!! AMIE Exam fee revised from Rs 2000 to Rs 3000 by sulemangani
[December 12, 2018, 07:01:18 PM]


DiesqueLW by uncopy
[November 06, 2018, 08:47:00 PM]


Re: Supermembership queries by praveen
[November 04, 2018, 09:39:26 AM]