What causes variations in microstructure of titanium?

[samara.]

hey, everyone,

i am really confused about microstructure of titanium,one is deformed and one is original both of them is 20x, have a look at the image attachment,


i know that the grey scratched is twinning and slip marks due to deformation, what about those white parts and black parts?

thank you...

 

[streeters]

Is this Cp-Ti (commercial purity) or another alloy like Ti-6Al-4V?
I'm guessing it is Cp-Ti because the first picture looks like equiaxed grains of alpha-phase.

The second image looks like widmanstatten phases. Was there a heat treatment on the alloy?
Check out this book on Titanium. It has a few good micrographs you can compare with:
http://books.google.co.uk/books?id=...AA#v=onepage&q=widmanstatten titanium&f=false

 

[samara.]

hi streeters,

thanks for helping, but this section is done,

the lecture said that...it was relatively pure titanium, the reason why lighter/darker region is due to its own orientation.

i feel it was not very good explanation, but it fits her marking scheme so m going to settle with that.