Friction Stir Processed D2 Thread

[Vamais]

I was recently given a friction stir processed D2 blade about 2 3/4" long, and I'm planning on making a handle for it. The blade appears to be a reject, and there are some grind mistakes and visible defects from the FSP process. Whether or not the edge metallurgy is what it was supposed to be is unknown, but I figured I'd post my knifebuilding process and observations about the steel here.

If anyone else has had experiences with FSP D2, feel free to share them here as well.

Here are two publications on the process:

https://www2.et.byu.edu/~sorensen/TMS%2 ... essing.pdf
https://www2.et.byu.edu/~sorensen/Tejon ... tation.pdf

I'll get a picture of the blade posted up soon.


-Vamais

[Vamais]

Here it is Rockwelled. Interesting results. looks like I'll have to re-shape and re-grind.

Side A:

Side B:

Rockwell C tests, ordered from kick to spine:
Side A:
45.6
43.9
44.4
64.6
66.1
66.5
64.5
49.1
44.2
44.4

Side B:
43.1
51.7
65.6
62.0
63.6
64.7
65.5
66.8
67.8
69.0
61.6
49.3

Tests were done with a Mitutoyo ARK-600.

[JRinFL]

Is it normal to see the HRC lower at the top and lower edge of the blade vs the middle? Or am I reading your list incorrectly?

[Vamais]

Is it normal to see the HRC lower at the top and lower edge of the blade vs the middle? Or am I reading your list incorrectly?

No it's not normal, and yes you are reading that correctly. Like I said, it was a reject. I am thinking that the steel was positioned impropperly when the blank was cut out, which is why the hard portion (the swath that looks more polished) is in the middle of the blade as opposed to the edge. I'll just have to remove all the excess material and regrind so I have a hard edge. It will be a smaller blade, but hopefully I'll still be able to get a good idea of how it performs.

[JRinFL]

Is it normal to see the HRC lower at the top and lower edge of the blade vs the middle? Or am I reading your list incorrectly?

No it's not normal, and yes you are reading that correctly. Like I said, it was a reject. I am thinking that the steel was positioned impropperly when the blank was cut out, which is why the hard portion (the swath that looks more polished) is in the middle of the blade as opposed to the edge. I'll just have to remove all the excess material and regrind so I have a hard edge. It will be a smaller blade, but hopefully I'll still be able to get a good idea of how it performs.

Thank you. The process seems very promising. Please keep us updated on your progress.