Composite blade sword!

[JParanee]

Very Cool Tank, I think that is great that you are working with your dad and I am sure he is very knowledgeable and has access to the equipment such as respirators etc. that are critical in working with carbon fiber that is if you are grinding or sanding it

Keep us posted and good luck

PS

I've got 4 kids and I'm sure he is very proud of you for all you do. be careful

 

[james terrio]

Tank, please let me take moment to thank you for sharing this project with us. I sincerely think it's a very interesting premise.

Let me take another moment to salute you and your father. It is flat-out awesome that you're working together and pushing some boundaries. Win, lose or draw, I guarantee that the experience will stick with you. :thumbup:

But for a sword to perform well it must be able to flex to a certain degree and return to center. I believe a sword that has a straight tempered piece of stainless with a carbon fiber outer layer would not stand up to this kind of stress well.

I understand your concerns. Flexibility of various steels has a lot more to do with geometry than it does with carbon/alloy content or hardness... I've owned cheap filet knives that can easily pass the bend test in your picture, many times over, all day long. Of course you're right that some alloys are better suited to swords than others, and 440C would not be my choice.

But I really don't think the flexibility of the core is a huge problem here... it does not need to be any thicker than the edge itself. That means almost any hardenable steel could be used. If anything, the core in Tank's project is too thick.

Again, my biggest doubt about this project is the CF itself, and the manner in which it's attached to the core.

 

[JParanee]

James to compare a thin filet knife that flexes with barely any pressure to a blade .33 thick being torqued over with a pipe is a horrible comparison

Come on I thought you where a knife maker

I understand you're point but there are better core steels for these folks to experiment with IMHO

And also a stainless that thin and at a 60 something Rockwell I believe will be prone to chipping and blowing out at the edge in an impact type tool like a sword

Also a blade that has a spring temper or that is differentialy heat treated in my experience is less prone to taking a set or breaking in sword type applications

 

[james terrio]

Come on I thought you where a knife maker

I suppose that depends on whom you ask

I understand you're point but there are better core steels for these folks to experiment with IMHO

Of course there are! I don't even use 440C for filet knives anymore... sheesh... what year is this, 1985?

CPM-3V would be my first choice for a project like this. Then again, CPM-3V is almost always my first choice.

 

[JCoutts]

First, I wanted to say that this thread is very interesting to me, it is an unusual sword to say the least and reading what James and JP have to say, well there is a lot of knowledge there.

As I have read this thread, I started wondering about the construction on the sword. Why use 2 sides of CF, why not use one larger piece of CF folded tightly over the spine of the sword? I may be way off the mark here, but I was just thinking that if it was constructed that way, you wouldn't have the sliding issue that you had in the one picture.

On another side note, to James and JP, what if a damascus core was used in something like this. Please realize, I am still very new to knifemaking, but I thought damascus combined some benefits of stainless and high carbon steels, so you could have a tough and hard blade. Like I said, I am new and I could be way off the mark here.

Also, if a damascus core was used it could give a really neat look to an already very cool idea.

Anyway, just my rambling/thinking.

 

[TankEpidemic]

The reason we just have two sheets on either side of the steel is because we had one big sheet of carbon fiber and we broke it into longer sheets, if we tried to bend it over the back of the blade we would just break the carbon we had at hand. As an added thought, the knife we made DID have the spine covered over in epoxy, the sword had the spine of the steel exposed. Hmmm....

 

[michael weedmark]

that is so cool.

 

[TankEpidemic]

Here is a photo of my father grinding on the sword to get it into shape. Though since now we figured out that you can just wet sand it to avoid all the splinters and dust.

Here it is finished. Too much is wrong with this sword so we just decided to put a simple wrap on the handle and just make it a wall hanger. My father plans to make another sword but with a wider blade so it doesn't twist and bend so much.

We finally got a chance to weigh the sword and it comes in at 293 grams.