FulanoDetailGlycerin: Sometimes used to keep specimens flexible and prevent them from becoming brittle, glycerin can be mixed with other preservatives.
Acetic Acid: This can be used in some preservation solutions to help maintain the pH balance and prevent decay.
Mothballs (Naphthalene): These are sometimes used to deter pests that might damage the specimens during storage.
It's important to handle these chemicals with care, as many can be toxic or harmful if inhaled or ingested. Proper safety precautions, such as using gloves and working in a well-ventilated area, are essential when working with these substances.”
Anyway, listing the most promising options that you could use (without compressing):
- Process-controlled optimization of the tensile strength of bamboo fiber composites for structural applications (pressed composites [not densified wood], achieved around 140 to 180 MPa)
- Development of flax/carbon fibre hybrid composites for enhanced properties - ScienceDirect (The only article that was able to reach 100 to 126 MPa or above using biofibers alone was this one, and it used bidirectional and unidirectional woven layers of Flax)
- Study of Effect of Surface Treatment on Mechanical Properties of Natural Fiber Reinforced Composites - ScienceDirect This one was able to reach around 200 to 300 MPa of tensile strength using pre-treated jute fibers.
- Recent advances in biodegradable polymers for sustainable applications | npj Materials Degradation (PLA composite with modified Harakeke or Hemp fiber achieved 100 MPa of tensile strength maximum)
- Mechanical Properties of Bioplastics Product from Musa Paradisica Formatypica Concentrate with Plasticizer Variables (this one reached 100 MPa, but is uses sorbitol)
- Advantages and Disadvantages of Bioplastics Production from Starch and Lignocellulosic Components - PMC (Manioc plastic reached 100 MPa of tensile strength, it redirects to a reference [link] and it is using starch from Manioc, not Manioc itself [still cheap tho])
- Scalable, Strong and Water-Stable Wood-Derived Bioplastic (delignified Balsa wood infused with vulcanized natural rubber achieved 180 MPa of tensile strength)
- Turning wood into plastic | ScienceDaily = https://sci-hub.se/10.1038/s41893-021-00702-w Achieved 120 MPa of tensile strength after a chemical treatment of the wood chip/powder with Choline chloride [expensive] and oxalic acid.
- Development of biodegradable and vermicompostable films based on alginate and waste eggshells - ScienceDirect (it actually achieves around 80 MPa of Tensile Strength)
- (PDF) Comparative analysis of the physical and mechanical properties of kraft paper and watercolor paper (120 to 282 MPa tensile strength)
- Properties and potential medical applications of regenerated casein fibers crosslinked with citric acid - PubMed (fibers achieved 110 to 130 MPa of tensile strength by themselves, maybe you could make something completely solid?)
- Effect of Nano-Fillers on Tensile Properties of Biopolymer Films | Request PDF (Composites achieved 120 to 150 MPa of tensile strength depending on the composition, but the materials can be expensive to buy)
- Performance of Gelatin Films Reinforced with Cloisite Na + and Black Pepper Essential Oil Loaded Nanoemulsion (achieved around 70 MPa to 150 MPa of tensile strength by adding Cloisite +Na, a nano montmorillonite clay with sodium carbonate. I have no idea what a montmorillonite clay is, but it is a type of phyllosilicate clay, which I also don’t know what it is. But accordingly to ChatGPT, it is most of the composition of Bentonite clays)
- Characteristics of Fiber Treatments on Tensile and Impact Strengths of Pine Resin/Areca Husk Fiber Biocomposites (Pine resin and Areca Husk Fibers untreated and treated with sodium hydroxide reached 148 to 164 MPa, but I don’t know if it is a solid object or a flexible fiber-like composite, since there is no compressive strength, I’d suppose it is the latter)
- Mechanical behaviour and damage mechanisms analysis of a flax-fibre reinforced composite by acoustic emission (200 to 300 MPa depending on the method)
About densified delignified infiltrated wood composites:
Although I couldn’t find any article talking about how to mold densified delignified infiltrated wood (I will call it “DDIW” for short), I do think it may be possible. And I’m not talking about making curved shapes or anything like that, I’m talking about complex, tridimensional shapes like lattices and the like.
Wood is normally bent and formed into other shapes using steam, and acrylic can easily be bent under heat.
So maybe there is the possibility of doing that to DDIW.
There is also the option of isostatic pressing.
Sources: Forming, Densification and Molding | SpringerLink Isostatic pressing of metallic powders [SubsTech]
There is also an ammonia bath to bend wood, but this is extremely hazardous.
I also don’t know how it affects the structural strength of the wood after the ammonia is removed.
Extreme wood bending with ammonia (in the video he says that the ammonia gets in between the wood cells, “ungluing” itself temporarily, so I wonder if the wood is too selective of this process. Maybe you could “unglue” everything with ammonia first, clamp everything together, and once the ammonia evaporates, it will glue again, but with the solid piece of wood that you added)
BENDING GUITAR SIDES WITH AMMONIA, TEST, at JONAH GUITARS
I found these papers talking about it, but although the densification process was successful, the molding of the pieces was questionable.
Yes, you can densify it, but not control the final shape very much.
Compressed and moulded wood from processing to products
Source: Chapter 5 - Powder Processes
List of DDIW composites that may be interesting:
- Large-Scale Manufacture of Recyclable Bioplastics from Renewable Cellulosic Biomass Derived from Softwood Kraft Pulp | ACS Applied Polymer Materials (This one said that the pressed delignified wood chips achieved 350 MPa of tensile strength, but again, how would you make complex shapes with this method?)
- Characteristics of Fiber Treatments on Tensile and Impact Strengths of Pine Resin/Areca Husk Fiber Biocomposites (Pine resin and Areca Husk Fibers untreated and treated with sodium hydroxide reached 148 to 164 MPa, but I don’t know if it is a solid object or a flexible fiber-like composite, since there is no compressive strength, I’d suppose it is the latter)
- (PDF) Fabrication and Design of Wood-Based High-Performance Composites (also densified delignified wood, from 60 to 250 MPa) Transforming wood as next‐generation structural and functional materials for a sustainable future (densified delignified bamboo wood, 600 MPa)
- Delignified Wood from Understanding the Hierarchically Aligned Cellulosic Structures to Creating Novel Functional Materials: A Review (also delignified densified biofibers 100 MPa, 600 MPa to 900 MPa depending on the process)
- Mechanical properties of transparent high strength biocomposites from delignified wood veneer - ScienceDirect (compressed transparent wood 270 MPa)
- Delignified Wood–Polymer Interpenetrating Composites Exceeding the Rule of Mixtures | ACS Applied Materials & Interfaces (500 MPa depending on the method)
If I were to test the resulting materials, I would improvise a test stand with a hydraulic jack and tie the test sample to the rope around the jack.
Like this, the example on the right would be useful to compress something.
I also thought of the possibility of using densified wood as fibers and then impregnating them with a polymer (such as PMMA) with vacuum molding.
However, I couldn’t find anything anywhere about the use of densified wood or bio-composites like that.
Which is quite the pain in the ass, it would be multiple times easier to compress wood fibers/bio-fibers in a roller and then wave them into composites…
You could make a composite using a mix and match of the materials listed and/or add fiberglass and other materials to increase strength.
By the way, if the 40 ton hydraulic cylinder was made out of these materials, it would reduce the weight from 50kg to 7kg.
Again:
This is the breaking strength of the materials.
Wood has a tensile strength around 100 MPa and a fatigue strength of 38 MPa, around ⅓ of the breaking strength.
You should also apply the same design considerations to the structural biocomposites that you may build.
I think I’m looking at these structural materials incorrectly.
They have low tensile strength, yes, but they have 3 to 4 times even more compressive strength.
Prestressed concrete - Wikipedia
The Beauty of Reinforced Concrete
Prestressed concrete increases the strength of the structure by compensating its lack of tensile strength by increasing the loads as compressive strength.
It only has 2 to 5 MPa of tensile strength and 17 to 70 MPa of compressive strength, yet it still is the backbone of every single building we have.
Maybe using the same technique on these composites, it would be able to withstand even greater stresses without issue.
Hell, maybe even without prestressing it would still be able to handle it.
Fibre prestressed polymer-matrix composites: a review
A Review of Prestressed Fibre-Reinforced Polymer Matrix Composites
Prestressed Composite Structures - Modeling, Manufacturing, Design
New Methodology for Prestressing Fiber Composites
Effect of prestress level on the strength of CFRP composite laminate
Option 4:
You can turn on the “F*ck it, we ball 9000” mindset and use a monocoque, truss or lattice (or all of these) design using metals, plastic, composites and/or using tensegrity designs with those ropes rated for 2 to 5 tons to keep everything together.
ChatGPT stated (with sources) that a monocoque/truss/lattice structure could be 30% to 60% lighter while supporting the same weight a solid structure would also support, it is meant to decrease the mass while maintaining strength. A design to increase strength-to-weight ratio.
If you use steel, aluminum or other material with easy access, then maybe you could weld a truss/lattice/monocoque design that could compete with composites in matters of weight savings.
The monocoque design is essentially how airplanes are made: the entirety of its weight is sustained by the metal skin nailed/welded to rib-cage-like rings.
Monocoque and Truss type structure 2.1.1.3 Simulations and AutoCAD | Download Scientific Diagram
Truss design (left) and semimonocoque design (right). | Download Scientific Diagram
Example of chassis main components. | Download Scientific Diagram
Bamboo Joints and Joinery Techniques
IsoTruss technology | inclusivedesign&mobility
The Secret to the Truss Strength!
There is a lot of information on the subject of truss designs, since it is a purely “mechanical” subject and not a “materials science and engineering” subject, so to speak.
On the subject, there are “truss systems” that people often design/build using 3D printers. I’m not saying a 3D printed mech would survive, but this can be a more approachable way of designing it.
TrusSystem by lpa - Thingiverse
Truss system by AlpinerBergen - Thingiverse
Complete Truss & Accessory Pack by D3D | Download free STL model | Printables.com
3D Printed Micro Truss Toy by Joe Flatley | Pinshape
Modular Truss Lap Counter Bridge EasyLap Mini-Z Miniz by Boehler - Thingiverse
https://www.thingiverse.com/thing:4933954
There are also Aluminum extrusions that are normally used in a lot of DIY projects, but these are expensive and the actual strength is not the objective of them.
construction profile and connectors by hallo_ralph - Thingiverse
Angle-Lock VS T-Slot Technology | Controlled Dynamics | Angle-Lock | 4K
There are 3D models for aluminum extrusions, maybe you could make a mold and make them either with metal or composites…? … And what about the screws/fasteners? Would they survive?
There are also modular lattice building blocks, but they are normally just the infill pattern of 3D print slicing programs. You could build and/or injection molding using them either as a filler for a composite or as the structure itself.
(I list these bunch of links because I readed all of them [or just the images] and I think they are useful)
Mechanical response of Ti–6Al–4V octet-truss lattice structures - ScienceDirect
The CLaP System: Chain-based Lattice Printing for Efficient Robotically-Assembled Structures
Probabilistic analysis of additively manufactured polymer lattice structures - ScienceDirect
https://cba.mit.edu/media/TLDR/index.html
Mechanical and Biological Characterization of 3D Printed Lattices
Computationally designed lattices with tuned properties for tissue engineering using 3D printing
The choice solely depends on how expensive and/or difficult each option is.
… But I was here, in this subject before, many project logs ago.
And I gave up on the idea because I couldn’t accurately design, build or predict how the structure would behave…
Why do I keep repeating the same thing over and over and over again…?
On the subject of metal lattices, I just now remembered about metal foams.
What is Metal Foam and Why Does it Work? | Sci NC
Production of metal foams using dolomite
Metal Foam - Innovation Nation
Open Cell Aluminum Foams Production by Replication and Porosity | Protocol Preview
Metal Foam Used to Protect the Military Could Be Used For So Much More
Weird Flexible Metal. A Simple Explanation #fabtech2023 (it is kinda foam, kinda isn’t, pretty neat tho)
From Paper to Bionics: Origami's Incredible Impact on Science | FD Engineering (origamis made out of metals are also being used as core materials, similar to foams)
You could make the Aluminum metal foam using the mentioned methods (using table salt and/or dolomite as the foaming agent) or using ceramic fiber spheres with sodium silicate as glue for the pores, which would also allow you to make lattices.
- I will fill the inner space of the aluminum foams with:
- Steel wires woven using a sock knitting machine for a metal composite for extra strength and weight saving.
- Rigid polyurethane foam
- Mixed with conventional epoxy resin
- And DIY flash graphene
- With lightweight fillers/additives, like hollow plastic spheres, hollow glass spheres, fumed silica, boron nitride silicon carbide powder etc. Anything that I can put my hands on and/or whatever the hell Tech Ingredients says. lol
- Maybe chopped glass fibers, these are cheap, but need specialized equipment. Wood saw and/or fibers are a good alternative too.
- For the motors I will use a mix of iron powder for the back iron and epoxy resin to secure the aluminum coils and even plastic/natural fiber knitting to secure them in place.
Although I was thinking of making a lattice structure, I’m still very tempted to make metal foams or “nanofoams”.
Combustion Synthesis of Ultrahigh Surface Area Metal Foams
Or I could make a lattice structure out of metal nanofoam…
I was thinking of either adding this metal foam inside of the metal lattice just like I was intending on filling lattices with PU/Epoxy foam or just the plain metal foam.
So, I was thinking of doing this steel foam by mixing steel powder with a sacrificial material. Pretty simple.
I was thinking of mixing metal nano powder with flux, nano-sized styrofoam powder and sodium silicate and then heating it until the sodium silicate melts off.
Sodium silicate/glass have a melting point around 1000ºC while stainless steel has a melting point of around 1400 to 1500ºC, even though glass is extremely viscous, at the temperature steel starts to soften/melt, they already have the viscosity of water.
You could use stainless steel nano powder, aluminum 7075 nano powder, or any other type of metal that you could easily source.
There is also the possibility of cold-welding the nano powder in a new object. You could mix the nanopowder with styrofoam powder and/or spheres, then use ultrasonic vibrations to weld the metal powder that is surrounding the styrofoam.
I do wonder if you could do that to wood, in order to proceed with the wood welding idea.
“Metals containing carbon cannot be cold welded together.”
Source: What is Cold Welding? (Advantages, Disadvantages and Applications).
“The reason for this unexpected behavior is that when the atoms in contact are all of the same kind, there is no way for the atoms to "know" that they are in different pieces of copper. When there are other atoms, in the oxides and greases and more complicated thin surface layers of contaminants in between, the atoms "know" when they are not on the same part. — Richard Feynman, The Feynman Lectures on Physics, 12–5 Friction“
Source: Cold welding - Wikipedia
So I would need to make an ultraclean metal nanopowder, without any kind of grease or impurity. So I don’t know if you could actually do that inside of a polymer.
I mean wouldn’t that be the same thing as adding metal nanopowder under vacuum inside a mold and then applying ultrasonic vibration to cold weld it?
Can you print 3D with iron in space?
So according to this stack exchange answer, it seems like cold weld isn’t that strong. But at least it could be useful to keep the nanofoam structurally rigid enough for the sintering/partial melting process.
In order to make the metal nano powder, you would need a ball mill.
How To Build a Ball Mill v2 for black powder (of course, just don’t use it for black powder)
“Duration: The milling process can take anywhere from 100 to 150 hours to achieve a uniform fine powder, depending on the desired particle size and material properties.
Nonionic surfactants do not carry a charge and can be less toxic, making them suitable for various applications. Examples include polyvinyl alcohol (PVA) and polyethylene glycol (PEG), which can help in stabilizing the nanoparticles without the risk of ionic interactions that might lead to aggregation.”
Functional Integrated Sandwich Structures for Vehicle Concepts of the Next Generation
There is also the process of sintering metals.
Supposedly, you can do that to any kind of metal. And maybe you use this process to make lattices?
What is iro3d metal 3D printer (2018) (dunno if this applies to sintering, but here it is anyway)
Delayed infill methods. Part 1: Puddle+Anchor and Puddle+Stand.
First Steel Attempt / Low Temp Sinter
A Walk Through the Powdered Metal Sintering Cycle
DIY Metal Injection Molding (HACKSMITH Tries MASTE)
Tensile and Fatigue Properties of Fe-Cu-C Sintered Steels | Scientific.Net
Microstructure and properties of Cu-Fe alloys fabricated via powder metallurgy and rolling
SINTERING OF POWDER PREMIXES - A BRIEF OVERVIEW
Debinding and Sintering in Metal Injection Moulding
Metal in the Microwave? 3D printed Steel Sintering #experiment #3dprinting
Making The Most Heat Resistant Material! (it may be useful aswell)
Once they cool down, you could also impregnate these metal foams with polymers, rubbers, resins, weld it to metal shells like in a monocoque design etc.
However, the properties of each type of metal foam heavily depends on its alloy, size of pores, density of pores, shape of pores etc.
Some articles that may help:
(I list these bunch of links because I readed all of them [or just the images] and I think they are useful)
Flexural Behaviour of Aluminium Foam/Composite Structures | SpringerLink
Fabrication and compressive behaviour of an aluminium foam composite - ScienceDirect
(PDF) Research on the Torsional Properties of Aluminum Foam-filled Steel Tube After Fire
The mechanical behavior of foamed aluminum | Journal of Materials Science
https://www.sciencedirect.com/science/article/abs/pii/S135964620100673X
The Deformation of aluminum foams | Metallurgical and Materials Transactions A
Failure of aluminum foams under multiaxial loads - ScienceDirect
Research Progress in the Preparation of Aluminum Foam Composite Structures
Thermal and permeability properties of metal aluminum foams for functional applications
I’d like to list a few modular structures that could be used as the “bone”/mold of the final structure, like wrapping fiberglass/carbon fiber into them and injecting it with epoxy (or similar). You could do the same thing with pipes (metal or plastic ones).
Snap-build Cellular Structure by whpthomas - Thingiverse (these two above are buildable lattice structures and could be interesting to make using metals and/or composites)
https://www.thingiverse.com/thing:4521702
https://www.thingiverse.com/thing:32955
Parametric Tetrahedral Lattice (Dual Extrusion) by dAcid - Thingiverse
Lattice Structures - Mikrostrukturen by RobotMama - Thingiverse
https://www.printables.com/model/78211-modular-structural-support-joint?lang=en
https://www.thingiverse.com/thing:4208800
Special Magnetic Modular Wire | 3D CAD Model Library | GrabCAD
hexagon, Robotic Assembly and Outfitting for NASA Space Missions | 3D CAD Model Library | GrabCAD
3D CAD Model Collection | GrabCAD Community Library
3D CAD Model Collection | GrabCAD Community Library
Printy Pipes - Construction Toy by 3d-printy - Thingiverse
Modular Pyramid Kit by tmeysson - Thingiverse
But I think I will stick with aluminum foams because they can be made from scrap (and convert it to 7075-T6 Al-alloy), and I will also fill them with rigid expanding rigid foam. Because it is dirt cheap for its density, it expands at least 10 to 50 times its initial volume (depending on the specific foam). You can use PU foam, Epoxy Foam, Polyester foam, so on and so forth. You can even mix conventional epoxy with the PU foam and DIY graphene for extra strength.
This is me from the future and right now I’m not so sure.
Yes, you can make it out of scrap.
But: you need to make an entire recycling, smelting, purification, casting and heat treatment for the hundreds of kilograms of soda cans, which is not safe, cheap or easy.
Observation:
Maybe you could mix epoxy and/or polyurethane with a foaming agent, similar to how it is done to foam concrete or aircrete:
Aircrete vs. Foamcrete: Which Is Better? - BuilderSpace.
But unlike in foam concrete, you can’t use a water based foam agent.
So you could use a few alternative options, such as obviously pump air, water steam, heated baking soda or mixing polymer spheres of materials with a different melting point. Styrofoam melts at 240ºC while HDPE melts at 130ºC, so you could actually make a HDPE foam like this.
Speaking of pumping air, you could use nano/micro bubble generators:
SIO Nanobubble Generator, UFB Hydrodynamic Cavitation - Slow Motion
Hydrodynamic Nanobubble EXPLAINER - GLOBAL CAVITATION
MNB400+SBT50 Micro-Nano Bubble system
How to generate microbubbles from a simple pump
Super waterize technology ～NANO BUBBLE～
DIY microbubble dual nozzle (swirling/vortex)
Blowing agent - Wikipedia (I always forgot of doing the obvious first, which is checking wikipedia)
There are commercial epoxy resin foaming agents and rigid expanded foam polyurethane/epoxy resins.
I’m just suggesting in case you are too broke to have access to these (like me).
I talked more about it on the OFF-Topic section, but there are some things called “unpoppable” bubbles.
UNPOPPABLE BUBBLE SOLUTION (hold bubbles without bursting)
Extracting Strawberry DNA to make Massive Bubbles
The bubbles are made from “molecular spaghetti” that are polymers, working like a fiber composite to the molecular level.
Just like the micro to nano sized spheres, you could make a composite using them in order to increase the strength of a composite.
You could even use needles (that have micro to nano sized holes) to make fibers of different sizes.
By the way, I will also be mixing the monocoque design with the lattice design, so it will have concentric hardshells with aluminum foam and rigid foam on the inside.
It is also possible to use really thin steel rebars (or even glass fiber rebars) and/or steel wires to allow an extra layer of structural integrity.
Which I will do.
Also, I will use iron powder and epoxy resin with thermal paste on the motors, more specifically, mixed with the resin.
The whole point of metal foam lattices is that they maintain a significant percentage of their structural strength while being 50% to 99% lighter, using a mix of monocoque (rigid shell with skeleton body) and rigid foams with super low density fillers (and graphene) is that they will maintain their structural integrity while being as light as possible.
In the structural 3D modeling section I will try to focus more on the exact percentage of strength that will be lost based on weight that will be saved, but I don’t think I will reach a definitive answer.
I have a lingering sensation that I’m overengineering the living crap out of this structure…
But I mean, I’m no engineer, so it will need to be as strong as possible.
… But… Even when I check calculators online, an impact/tension or other loads applied on a random cross-section of this structure, even with values reaching 5000kg, less than 1 MPa is suffered throughout the structure.
But I don’t know how to tell if this is correct or not…
There is also Iron Aluminide, Nickel Aluminide and Magnesium Aluminide.
Iron aluminide seems a really good option because of price and accessibility, but I can’t find many sources listing the exact composition of iron aluminide, unlike aluminum 7071.
In this source it is said that the iron aluminides can achieve 800 MPa of yield strength:
Fe–Al–Si-Type Iron Aluminides: On the Strengthening by Refractory Metals Borides - PMC
The only issue is that I don’t know what should be the temperature of alloying, if it should be the melting temperature of iron (1500ºc) or the melting temperature of aluminum (+/- 700ºC).
Just now I found out about Aluminium-Magnesium-Zinc alloys:
Study on the tensile properties of Al-Zn-Mg alloy based on molecular dynamics - ScienceDirect (this one says it has 6 GPa of tensile strength, which is 6000 MPa, maybe they are talking about young’s modulus, which can indeed be that high)
Aluminum zinc magnesium alloys | Total Materia
“Thus, ultimate tensile strengths of up to 900 MPa and yield strengths to 850 MPa are reported, but with elongations of not more than 1%. “
Actually, forget it, it is just an Aluminum 7xxx series, just like Aluminum 7075.
“The Al-Zn-Mg-Cu (7xxx series) alloys have been extensively used in aeronautics and astronautics fields due to their excellent properties such as high specific strength, high fracture toughness and superior corrosion resistance (Osten et al., 2020; Jiao et al., 2018).”
You can make it out of lattices with metal foam, lattices with composites, trusses with metals, trusses with composites, so on and so on.
Observation 2:
You can use electrolysis to cut steel plates into whatever shape you want without any dangerous chemicals, TIG/MIG welders or molten metal furnaces.
However, you would need to eventually find a way of joining the pieces together, either by interlocking parts or something else.
How To Cut Steel With Electrolysis [Experiment In Progress] - NightHawkInLight
How to make reedvalves for pulsejet engines
Apparently this is called “Electrochemical machining”, similar to “Electrical discharge machining”
Electrochemical machining - Wikipedia
Cut and Engrave Any Metal: Electrochemical Machining and Jet-ECM
Photo Chemical Machining Process - Northwest Etch
How to make precise sheet metal parts (photochemical machining)
DIY homemade electrochemical machining ECM, first test run.
The Art of Pulsed Electro-Chemical Machining
Ender 3 Electrochemical Mill Conversion [OPENSOURCE]
Electrochemical Boring Machine (ECBM)
I 3D printed a 4-axis wire EDM machine that can cut anything conductive (not ECM, but you could easily modify it)
You can use any conductive material and any chemical with this technique, but stronger (and more dangerous) solvents/acids can be faster and more precise.
I mean, you could take a solid piece of steel (or any other metal) and then use baking soda to turn it into a lattice structure, but how long would it take?
(and how much would it cost to find a solid piece of steel in the proportions you want?)
I found a few papers talking about electrochemical joining of metals, but they aren’t as direct as the electrochemical machining.
In most cases they use electroplating of metals to join them together, normally using copper or nickel.
Electrochemical joining: process, applications, and property ..|INIS
(PDF) Corrosion behaviour of electrochemically joined aluminum and stainless steel
Not gonna lie, although you don’t exactly weld these metals together, I do think it could result in a cheap and strong structure, especially since you wouldn’t need kilograms upon kilograms of nickel electrolyte.
Ultralight Metallic Microlattices
Stronger 3D Printed Parts with Electroplating
Electroplating - Easy DIY Nickel, Copper, Zinc Plating
Copper Electroplating On Another Level - Paint Metals With Electroplating
NASA's clever technique to make combustion chambers
Maybe you could turn it into a 3D printer?
Yes you can.
Electrochemical deposition is a thing, and you could make thermo-responsive composites that work just like shape memory alloys, but not as expensive.
Low cost metal 3D printing! Electrochemical additive manufacturing (it is showed in this video, but it uses copper and nickel, both are somewhat expensive and heavy, but there aren’t the only metals that exist)
R&D 100 Winner 2023: Electrochemical Additive Manufacturing (Electro 3D)
Electrochemical additive manufacturing DIY 1h run and results...
ECAM 3D Printing Explained: Advanced Metal 3D Printing by California Technical Media
Jet/flow based micro-electrochemical additive manufacturing (μECAM) and Meniscus-confined μECAM.
Just like every video pointed out: it is slow as hell.
Unless you use more reactive (and dangerous) chemicals, you will be looking at a 1 month printing time.
By the way, according to this article the tensile strength of electrodeposited nickel is around 300 to 400 MPa (while heat-treated nickel metal can reach around twice that strength).
Measured material properties of electroplated nickel. | Download Table
But I hear that the best course of action is to heat treat the electrodeposited metal in order to make it more structurally resistant and to drive off hydrogen molecules stuck inside of it.
That makes me remember that electroplated carbon fiber composite that I saw here on Hackaday a time back.
Electroplating Carbon Fibers Can Have Interesting Results | Hackaday
Self-Created Metal Composites | Hackaday.io
I guess it would in fact, be strong enough.
You could even mix it with electrodeposited copper in order to make a superalloy such as monel.
However, it would be too expensive, assuming that you would use electroless metal deposition and carbon fiber.
Even if you use other conductive materials, like cheaper metals, conductive polymers or just any material coated with a conductive layer (like the wax-graphite rocket nozzle), it would still be a super slow process. Especially if you want to make thicker pieces.
Also, if you are working with composites, maybe this will help:
In essence, composites like carbon fiber or glass fiber can’t really be used with rivets, screws, nuts and bolts. So, what is the best way of reversibly joining composite parts together, like you do with screws and bolts?
Well, ideally, you would use a reversible glue that would stop working on command, like the electro adhesive joints. Then, join the exposed fiber composites together with something similar to a knit/knot or whatever and finally add the reversible glue again.
Sources: Analysis of knitted fabric reinforced composites: Part I. Fibre orientation distribution - ScienceDirect Lightweight weft-knitted tubular lattice composite for energy absorption applications: An experimental and numerical study - ScienceDirect
However, there aren’t any types of “reversible” glues that can also be as structurally strong as epoxy resins (most “reversible glues” being suggested are thermoplastics that can be melted away, like PEEK polymer, but that costs 500 dollars per kilogram).
Thus, the best compromise would be to remove the epoxy resin (chemically, thermally, electrochemically etc) from the fibers.
How to Remove Epoxy from Surfaces - Entropy Resins
Recycling Technique of Carbon Fiber Laminate Using Hydrolysis Near Critical Region | Scientific.Net
Recycling of carbon fiber reinforced polymers in a subcritical acetic acid solution - PMC
JOINING OF FIBRE-REINFORCED POLYMER COMPOSITES
You can coat the parts that must not react with the solvents with a chemically resistant/inert material and the non-coated epoxy goes in the middle, but I don’t know how strong this joint/fastener would be. Since this “middle” epoxy is facing a material that isn’t epoxy, nor a fiber, it wouldn’t be bonding very well and it would require to be strong on its own instead of relying on the integrity of the whole piece, like conventional fiber composites.
A few plastics that are resistant to these chemicals: PTFE (aka teflon), nylons, polyesters and acetals.
You could also use electrodeposition of metals such as: nickel, chrome, zinc and copper.
You could do all of that dance or work with “Reversibly assembled cellular composite materials”, if you are crazy enough.
Reversibly assembled cellular composite materials - Wikipedia
Source: Compressive properties of reversibly assembled lattice structures
Sources: Reversibly Assembled Cellular Composite Materials Digital Morphing Wing: Active Wing Shaping Concept Using Composite Lattice-Based Cellular Structures | Soft Robotics
Discretely assembled mechanical metamaterials | Science Advances Discretely assembled mechanical metamaterials
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