How to tell ductile vs brittle fracture using fractography

Ductile vs brittle fracture will both involve crack initiation and crack propagation. However, these failure modes look very different. A ductile material can deform in the presence of a crack to reduce stress and in doing so can prevent spontaneous crack growth. A brittle material cannot deform (much) so crack propagation is spontaneous. The fracture surface can be investigated to tell which mode occurred. This is called fractography. Ductile fracture surfaces tend to be rough and cup and cone shaped. Brittle fracture surfaces tend to be flat with characteristic flaw, mirror, mist, and hackle regions pointing to the flaw responsible for failure.

[@marcsokol6268]

What a wonderfully concise and understandable introduction to brittle vs ductile fracture on both the macro and micro level (and how the two relate to one another). I am a structural engineer who was looking for just this type of intro so I could better understand some fractographic data from a failure analysis I have been reading. Thank you for the very well done presentation!

[@TaylorSparks]

Thanks!! I've got loads of materials science videos and a cool podcast called Materialism you might like.

[@vishank7]

Can you please explain why we have the mirror-mist-hackle on the surface of a brittle fracture? It seems really interesting! Also, what decides whether a specimen will have the chevron markings or the mirror-mist-hackle pattern? Thanks already!

[@TaylorSparks]

this is a great resource to learn more. www.corning.com/media/worldwide/cdt/documents/2_TIP_201.pdf

[@cristianortiz3349]

Good video!

[@user-ky3js3dd4u]

I need case studies for such a fracture such as titanic ,, suggest papers and books or any thing might help

[@_SomyaY]

your vids were gold! wish i could find such videos/profs for other courses too 🥲🥲