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Liquidmetal Blades, Knives, and Other Sharp Things

 

Because Liquidmetal alloy is hard like a ceramic, stiff like steel, elastic like a plastic, and corrosion resistant like it has been given an expensive coating, a keen area of interest is in blade or blade-like applications. This is not surprising, especially given the nearest-to-net(tm) shape moldability of our alloy.  In fact, we are currently investigating new applications where precise piercing of metal foils with high repeatability are required.

However, it does beg the question: "how sharp a blade can you mold?" This is a great question asked on our Function & Finish blog post, and one which we thought deserves its own blog post in response.  We hope this blog post will be interesting to you, especially if blades are your business.

First, Liquidmetal alloy has been demonstrated in knife applications in the past, and even won several awards and magazine front-page features as a revolutionary blade material. Scuba gear dive knives were a special area of interest due to the exceptional resistance of Liquidmetal alloy to salt water corrosion.

Liquidmetal Knives                Blade May 2003

These knives in the past were laboriously ground to their final dimensions from cast bars of Liquidmetal alloy, and distributed to a limited number of enthusiasts, who were considerably excited about the material advantages. Unfortunately, these elegantly shaped and custom handled knives which made their way into circulation were so rare and exotic they are now collector’s items.

Untitled

Fast forward to the present…

Liquidmetal Technologies believes it is now positioned to manufacture any moldable geometry with a substantially improved casting technology. Our working design-guide calls for a minimum radius on all corners of 0.2 mm which allows for laminar fluid flow throughout the part and consistent 100% fill factor. Therefore, a blade geometry with a 200 um (0.2 mm) radius on the cutting edge of the blade could be easily molded today in Liquidmetal alloy, followed by a simple grind, etch, or other technique to finish the edge to the customer’s specification.

cast corner radius exampleBut to take this further, let’s assume that an as-molded sharp is required. In this case, it is theoretically possible to generate curvatures well under the 0.2 mm guideline if certain mold geometry conditions are met. The figure to the right shows a cross-section of an as-molded Liquidmetal part with a sharp 90 degree angle where the filled corner radius has been measured to be 5.9 um (0.0059 mm). The inset image shows the same corner magnified at 1000x with the measurement detail.

The final piece of the puzzle is the question: “how sharp is sharp?” To answer that question, let’s compare our 5.9 um radius to the curvature on the edge of a commercial razor blade. The scanning electron microscope image below (borrowed from http://www.bladeforums.com) shows a 3,000x image of a razor edge, measured to have a diameter of about 0.4 um, or about an order of magnitude smaller than our as-cast edge.

Gillette blades

Considering that we have done nothing to sharpen the 90 degree corner on our as-molded Liquidmetal part, we think that this could be something that is interesting to pursue.  Our unoptimized sharp edge is only an order of magnitude lower than a brand-new razor blade.  Our new processes may now finally be ready to support an application that can take advantage of our ability to replicate sharp features. 

If you’d like to explore an opportunity in this area, please contact us here.

Comments

How intricate a design can be done? For instance, could a turbo impeller be molded? And if so, can liquid metal withstand that kind of heat which it would be subjected to? 
 
thanks
Posted @ Tuesday, June 04, 2013 2:28 PM by Walt
Assuming that you can achieve the .4 um edge with liquidmetal, how well would it hold the edge? Longer than a razorblade?
Posted @ Wednesday, June 05, 2013 12:53 PM by Jim McLeod
Hi Walt. A turbo impeller could be molded, depending on the design. Liquidmetal can operate up to 250C.  
 
Jim. We have some evidence that it would hold an edge very well. We have actually just made a R&D blade for a customer to test, so we will see what results return from that.
Posted @ Thursday, August 08, 2013 7:26 PM by Glenton Jelbert
Are VMatter knives made by LiquidMetal?
Posted @ Saturday, August 24, 2013 3:48 PM by Richard
So liquid metal is limited with regard to heat. Anything above 250C destroys the composistion? 
 
250C is not that "hot". 480F and that's it? So it would have to be used for applications not subject to heat stress. Right? 
 
TIA
Posted @ Monday, September 16, 2013 12:48 PM by Frank
Am I to understand from the comments above that your liquid metal could be rolled into coils of metal that would have different widths and different thicknesses so as to allow the coils to be used in high speed mass production progressive, compound and transfer dies? If so, would the metal have to be heated to a certain temperature as it passed through the dies? If your liquid metal were to trade on a commodity exchange, are you able to disclose at about what the price would be per oz./lb. ? Thank you 
A Stockholder
Posted @ Saturday, October 05, 2013 8:46 PM by Tom Aye
I noted one of the photos shows a laser marked knife. Is there a problem with Beryllium outgassing, or has that been solved? Besides doing dark marking, how well does this material laser engrave? 
Thanks
Posted @ Tuesday, October 08, 2013 7:29 PM by Mark
Excellent advice! you don't know how many marketers need to have these traits ingrained into them. Kudos!
Posted @ Thursday, October 10, 2013 2:52 AM by Diving Lessons Melbourne
I am very interested in the 'razor' sharp blade application. Have you investigated edge retention strategies? Are there environmental storage concerns or opportunities as edges are minimized? Is there a point in the hardening or curing process where Liquidmetal alloy could be roll compressed or extruded to a final sharp edge? Similarly, is there a superior point immediately after forming which best accommodates final edge polishing or laser finishing.
Posted @ Saturday, October 26, 2013 4:27 PM by Tom Morley
Hi Glenton, can you say what were the results of the test with the R&D blade you made for the customer? Thanks...
Posted @ Thursday, October 31, 2013 1:35 AM by Stefan
It's still in the works, Stefan.
Posted @ Monday, November 04, 2013 12:36 PM by Glenton Jelbert
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