Titanium Blade

[Lillis]

So i just finished my first titanium blade knife, and it took me about 45min+ It was a high quality, expensive kitchen knife

My own experience (trail and error) is that i could only use a very high angle. When i tried on lower angles the edge showed small, small marks in it. Looked like small cracks, even with the SJ-250 stone

I would guess, 35°+ each side.

I remade the bevel on the knife 3 times, before i could get a clean, nice edge.

The "customer" was so happy with the knife, they had tried to get it sharp many times but failed so it was well worth the time

What are your thoughts and recommendations for titanium blade knifes? It sure was not easy to get a nice edge....

[grepper]

It would be interesting to know more about the knife.  What brand was it?  My guess is that the blade is a hard steel alloy with a TiN coating.  Does a magnet stick to it?  Was the bevel a different color than the rest of the knife?  Titanium is way too soft to make a good blade, and even common industrial Ti alloys are only somewhere in the 30 -50 HRC range.  That wouldn't hold an edge very well, but it won't rust!  I think they use titanium in diving knives used in salt water or other blades that must withstand corrosive environments.

I wonder if the small marks that looked like cracks you saw on the blade was scratching or actual chipping or splitting of the edge?  You can tell a lot about what is happening with just a good magnifying glass or better yet a microscope.  The fact that you had to sharpen to 35°+ makes me wonder.  That's more like a cleaver.   I've seen that happen on hard brittle steel, and crappy steel too.  Until you figure it out it can be really frustrating to sharpen!

[Herman Trivilino]

I also have seen this type of thing happen with very cheap (i.e. crappy) knives. I agree that without a good magnifier it's difficult figure out what's going on. I like my 40X dissecting microscope because it also gives me a wide field of view.

I wonder what the original angle was. I suspect that this knife was made to never be sharpened. As Mark said, likely there was a plating of some kind of hard alloy that was worn away as soon as it touched the grindstone. Now you've exposed some crappy steel that likely will never hold an edge for very long.