Deformation of metals, Other Engineering

Q. Explain the following with reference to deformation of metals:

                        (1) Preferred orientation

                        (2) Elastic after effect

                        (3) Bauschinger effect

Ans. (1) Preferred orientation: It is a condition of polycrystalline aggregate in which crystal orientations are not random under certain conditions the crystal is a metal tend to align themselves in a common axial direction. Such a direction is known as a preferred orientation.

       Preferred orientation occurs when certain crystallographic planes, tend to orient themselves in a preferred manner with respect to the direction of maximum strain.

(2) Elastic after effect: Consider a metal which is subject to sudden constant stress at a level below the elastic limit.

     After an initial instantaneous strain, the metal will gradually creep until the strain reaches an essentially value.

      If the load is removed suddenly, the strain drops instantaneously, but not at all a certain amount of strain still remains that solely decrease with time, approaching its original value. The time dependence of strain is called the elastic after effect.

(3) Bauschinger Effect: If in a metal the flow is started at certain stress intensity in one direction in one slip plane system, and subsequently the sign of the stress is reversed then flow in the reverse direction will initiate at a lower stress level.

       Let a material has the yield stress in tension as 'a' and the same in compression as 'x'. If is a new specimen of the same material is loaded in tension past the limit yield stress to 'b' along the path 'q, a, b' and then it is unloaded it will flow the path 'b, c'.

     If now, the specimen is subjected to reversed stress compressive stress the plastic flow will begin at the stress corresponding to point 'd' which is apparently lower than the original compressive yield stress of the material corresponding to point 'x'.

      Thus, while the yield stress in tension was increased by strain hardening from 'a' to 'b' the yield stress in compression is decreased from 'x' to 'd'. This effect is Bauschinger effect.

Posted Date: 8/1/2012 9:08:50 AM | Location : United States







Related Discussions:- Deformation of metals, Assignment Help, Ask Question on Deformation of metals, Get Answer, Expert's Help, Deformation of metals Discussions

Write discussion on Deformation of metals
Your posts are moderated
Related Questions
Ten projects only agricultural engineer will have say

You are required to undertake the following tasks: 1.      Problem Identification Download the dataset assigned to you from the module Blackboard site. Read the data description

If radial velocity is neglected, for a stat or there is no change from the cascade analysis. For a rotor this vectorial For a rotor this vectorial addition gives rise to graphical


Seekers   There are two main types of sensor used in autonomous vehicles (seekers and position/attitude sensors) - although not all systems have both.            - Airc

We now have some idea about what models are available to simulate the flow over an aerofoil, and also how to use the Hanley package to apply these methods. Keep referring to you

PROPELLER TRACK An out of track propeller will suffer an imbalance caused by the Dynamic and Aerodynamic being out of balance. Propeller track is the path followed by a blad

Noise Suppression in Aircraft Design: It has been seen that the first step towards noise suppression is at the design stage of the rotating and static parts of the engine. The

how to become robotics engneer

Hot Section Inspections (HSI's) The hot section includes all components in the combustion and turbine sections of the engine. Scheduled inspections may involve visual inspectio