where expertise comes together - since 1996 -

The Largest Open Access Portal of Nondestructive Testing (NDT)

Conference Proceedings, Articles, News, Exhibition, Forum, Network and more

where expertise comes together
- since 1996 -
1122 views
Technical Discussions
XiangYan
XiangYan
06:51 Sep-05-2008
coercive force

is the coercive force depend on the shape ? Provided two samples are made of the same material but different shape, you measure their coercive force could you end up with different results ?



 
 Reply 
 
Michel Couture
NDT Inspector,
consultant, Canada, Joined Sep 2006, 869

Michel Couture

NDT Inspector,
consultant,
Canada,
Joined Sep 2006
869
07:24 Sep-05-2008
Re: coercive force
In one word, YES! The lower the L/D Ratio (Length to Diameter), greater is the Coercive Force required to demagnetise the item. But shape is not the only factor. You also have to take into account such properties as heat treatment and alloying.

Cheerio's
Michel

----------- Start Original Message -----------
: is the coercive force depend on the shape ? Provided two samples are made of the same material but different shape, you measure their coercive force could you end up with different results ?
------------ End Original Message ------------




 
 Reply 
 
Catalin Mandache
Catalin Mandache
06:03 Sep-08-2008
Re: coercive force
The coercive force depends on so many micro structural factors that is very unlikely to have the same values for two identically shaped and alloyed samples.

----------- Start Original Message -----------
: is the coercive force depend on the shape ? Provided two samples are made of the same material but different shape, you measure their coercive force could you end up with different results ?
------------ End Original Message ------------




 
 Reply 
 
David Mackintosh
Engineering,
Acuren Group Inc., Canada, Joined Feb 2011, 85

David Mackintosh

Engineering,
Acuren Group Inc.,
Canada,
Joined Feb 2011
85
09:36 Sep-23-2008
Re: coercive force
----------- Start Original Message -----------
: is the coercive force depend on the shape ? Provided two samples are made of the same material but different shape, you measure their coercive force could you end up with different results ?
------------ End Original Message ------------

The coercive force, Hc, is the applied field required to demagnetize a material after saturation. It is a material property. (See for example http://www.ndt-ed.org/EducationResources/CommunityCollege/MagParticle/Physics/HysteresisLoop.htm and http://en.wikipedia.org/wiki/Coercive_force.) The magnetic H-field required to demagnetize a specific object depends on the material properties, the shape of the object, and the method of applying the field, among other things. Hc for the material and the demagnetizing force required for a specific object are related, but it is not always easy to calculate one from the other.

David



 
 Reply 
 

Product Spotlight

AMIGO2

TSC Amigo2 - ACFM technology has developed a solid reputation for accurately detecting and sizing
...
surface-breaking cracks through paint and coatings. As the industry demands increased performance in speed, signal quality, and portability, it’s time for an evolution. It’s time for Amigo2.
>

Navic - Steerable Modular Automated Scanner

The Navic is a modular, motorized, steerable scanner designed to carry multiple attachments used
...
in various scanning and inspection applications. The Navic is capable of weld scanning (girth welds and long seam welds), automated corrosion mapping, and tank scanning.
>

High-performance Linear Phased Array Probes

Available to order from stock in a range of 5MHz – 7.5MHz and from 16 to 64 elements. Designed w
...
ith piezo-composite elements, Phoenix phased array probes provide high-resolution imaging to maximise sensitivity; accurate ultrasonic detection and sizing of defects in welds; and effective corrosion mapping. Housed in a rugged stainless steel case for on-site industrial NDT applications.
>

Teletest Focus+

Teletest Focus+ electronics have superior capabilities than rivals on the market. Beyond the usual
...
test features, Focus+ has 24 transmit channels and 24 receive channels, with an additional on-board switching capabilities. The instrument's frequency range is 10–300 kHz.
>

Share...
We use technical and analytics cookies to ensure that we will give you the best experience of our website - More Info
Accept
top
this is debug window