Magnetically assisted slip casting

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Magnetically assisted slip casting is a manufacturing technique that uses anisotropic stiff nanoparticle platelets in a ceramic, metal or polymer functional matrix to produce [1] layered objects that can mimic natural objects such as nacre. Each layer of platelets is oriented in a different direction, giving the resulting object greater strength. The inventors claimed that the process is 10x faster than commercial 3D printing. The magnetisation and orientation of the ceramic platelets has been patented. [2]

Contents

Technique

The technique involves pouring a suspension of magnetized ceramic micro-plates. Pores in the plaster mold absorb the liquid from the suspension, solidifying the material from the outside in. The particles are subjected to a strong magnetic field as they solidify that causes them to align in one direction. The field's orientation is changed at regular intervals, moving the plates still in suspension, without disturbing already-solidified plates. By varying the composition of the suspension and the direction of the platelets, a continuous process can produce multiple layers with differing material properties in a single object. The resulting objects can closely imitate their natural models. [2]

Artificial tooth

Researchers produced an artificial tooth whose microstructure mimicked that of a real tooth. The outer layers, corresponding to enamel, were hard and structurally complex. The outer layers contained glass nanoparticles and aluminium oxide plates were aligned perpendicular to the surface. After the outer layers hardened, a second suspension was poured. It contained no glass, and the plates were aligned horizontally to the surface of the tooth. These deeper layers were tougher, resembling dentine. The tooth was then cooked at 1,600 degrees to compact and harden the material — a process known as sintering. The last step involved filling remaining pores with a synthetic monomer used in dentistry, which polymerizes after treatment. [2] Hardness and durability approximated that of both the enamel and dentine of a tooth. [3]

See also

Related Research Articles

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Anisotropy is the property of a material which allows it to change or assume different properties in different directions, as opposed to isotropy. It can be defined as a difference, when measured along different axes, in a material's physical or mechanical properties.

Liquid crystal State of matter with properties of both conventional liquids and crystals

Liquid crystal (LC) is a state of matter that has properties between those of conventional liquids and those of solid crystals. For instance, a liquid crystal may flow like a liquid, but its molecules may be oriented in a crystal-like way. There are many different types of liquid-crystal phases, which can be distinguished by their different optical properties. The contrasting areas in the textures correspond to domains where the liquid-crystal molecules are oriented in different directions. Within a domain, however, the molecules are well ordered. LC materials may not always be in a liquid-crystal state of matter.

Crystallite

A crystallite is a small or even microscopic crystal which forms, for example, during the cooling of many materials. Crystallites are also referred to as grains.

Dentin Calcified tissue of the body; one of the four major components of teeth

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Nanocomposite

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This is a list of pottery and ceramic terms.

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Crystallization of polymers is a process associated with partial alignment of their molecular chains. These chains fold together and form ordered regions called lamellae, which compose larger spheroidal structures named spherulites. Polymers can crystallize upon cooling from melting, mechanical stretching or solvent evaporation. Crystallization affects optical, mechanical, thermal and chemical properties of the polymer. The degree of crystallinity is estimated by different analytical methods and it typically ranges between 10 and 80%, with crystallized polymers often called "semi-crystalline". The properties of semi-crystalline polymers are determined not only by the degree of crystallinity, but also by the size and orientation of the molecular chains.

Ceramic nanoparticle

Ceramic nanoparticle is a type of nanoparticle that is composed of ceramics, which are generally classified as inorganic, heat-resistant, nonmetallic solids that can be made of both metallic and nonmetallic compounds. The material offers unique properties. Macroscale ceramics are brittle and rigid and break upon impact. However, Ceramic nanoparticles take on a larger variety of functions, including dielectric, ferroelectric, piezoelectric, pyroelectric, ferromagnetic, magnetoresistive, superconductive and electro-optical.

Freeze-casting

Freeze-casting, also frequently referred to as ice-templating, or freeze alignment, is a technique that exploits the highly anisotropic solidification behavior of a solvent in a well-dispersed slurry to template controllably a directionally porous ceramic. By subjecting an aqueous slurry to a directional temperature gradient, ice crystals will nucleate on one side of the slurry and grow along the temperature gradient. The ice crystals will redistribute the suspended ceramic particles as they grow within the slurry, effectively templating the ceramic.

References

  1. Le Ferrand, Hortense; Bouville, Florian; Niebel, Tobias P.; Studart, André R. (2015-09-21). "Magnetically assisted slip casting of bioinspired heterogeneous composites". Nature Materials. 14 (11): 1172–1179. arXiv: 1605.07461 . Bibcode:2015NatMa..14.1172L. doi:10.1038/nmat4419. ISSN   1476-4660. PMID   26390326. S2CID   37712925.
  2. 1 2 3 Micu, Alexandru (September 29, 2015). "Artificial tooth is as good as the real deal". ZME. Retrieved 2015-09-29.
  3. Watry, Greg (September 29, 2015). "Creating Fake Teeth as Strong as the Real Deal". R&D. Retrieved 2015-09-29.