All of the commercial ceramic AM technologies in the 3dpbm map of Ceramic Additive Manufacturing (from 3dpbm’s just-released Ceramic Additive Manufacturing Opportunities and Trends report) are based on the process of bonding ceramic particles into the shape of a 3D object, then placing them as pillars in Sintering in a furnace – processing step.Unlike metal AM, which is a relatively new and independent family of technologies, all-ceramic AM hardware technology comes from the family of bonded materials.For this reason, growth in this segment is more limited, but it also opens up opportunities for emerging metal AM technologies (bonded filament, metal binder jetting) that work in a similar way.Also, although they require sintering in a furnace, most bonded material technologies are considered producible processes.So ceramics was born and continues to evolve as a production method, also for prototyping, rather than a prototyping method that is evolving into production (as is the case with many polymer and metal additive manufacturing technologies).
Another seemingly surprising (and possibly frustrating) fact is that there is currently no commercially available powder bed fusion process for ceramics.Attempts have been made in the past, and dozens of published studies have attempted and continue to attempt to demonstrate the viability of direct laser sintering of ceramics as a production method.However, the challenges associated with direct laser sintering of ceramics, mainly due to the extremely high temperatures required to sinter or melt ceramic powders, have prevented these processes from being a viable commercial opportunity.Hybrid processes, in which lasers operate on materials combined with ceramic powders in a single process, have been trialled, but have so far had limited commercial success.
However, as the metal additive manufacturing industry realizes that binder jetting may ultimately provide the fastest production rates, ceramic additive manufacturing technologies (as shown in the 3dpbm map of ceramic additive manufacturing) have made significant progress in the field.Likewise, as metal additive manufacturing begins to accept that incorporating wire technology can provide the most cost-effective and office-friendly solutions, the same technology can easily (and is being) applied to ceramics.Finally, as the metal additive manufacturing industry discovers the high-resolution capabilities combined with metal paste stereolithography, this technology has found great application in ceramic additive manufacturing.
While the stereolithography (SLA) process is primarily associated with polymer 3D printing materials, the process is also suitable for producing ceramic parts.As shown in the Ceramic Additive Manufacturing Technology Map, stereolithography is the most recognized and reliable technology for 3D printing ceramic materials.In the ceramic stereolithography process, a ceramic slurry layer made of a monomer resin with a high ceramic content is cured using a light source.This light source varies by technology.For example, SLA systems will use lasers to cure pastes, while DLP printers rely on digital micromirror projectors.The monomer resin hardens when exposed to a light source (a photopolymerization process), binding the ceramic particles within the polymer matrix.Because the ceramic stereolithography process produces green printed parts, it is often accompanied by post-processing, including heat treatment to remove binders and sintering to produce fully dense ceramic parts.
Binder jetting uses selective application of a binding fluid to bond powder materials in layers.It is similar to inkjet printing, but instead of applying ink to a sheet of paper to create a two-dimensional product, a binder jet printer bonds individual powder layers to create a three-dimensional object.In ceramic additive manufacturing technology, binder jetting avoids common shrinkage defects and allows the creation of complex shapes.Other advantages include part support from surrounding powder, relative ease of degreasing and suitability for large and medical grade parts.Common materials include sand and cement, technical ceramics such as silicon carbide and boron carbide, and to a lesser extent oxide ceramics such as alumina and zirconia.Binder jetting is arguably the most efficient process for ceramic tools, molds and casting cores.Key variables include ceramic material, bonding method and mechanism, and post-processing steps such as de-powdering and densification.
Fused filament fabrication (FFF) is the most common 3D printing technique due to its cheap printers and wide range of available materials.To print ceramic components via FFF, several companies have developed highly filled ceramic materials (ceramics in thermoplastic matrices) and introduced complete process chains.Typically, materials with a 50% ceramic content can be printed with nozzle sizes as small as 150 microns.Layer thicknesses of 80 microns and strip widths of 160 microns can be achieved using the open demo structure.However, parts printed by this method have not yet achieved post-sintered densities comparable to stereolithography or ceramic injection molding, limiting the range of possible applications in the field of advanced ceramic parts.During extrusion and deposition printing, holes and cavities are introduced, although these can be gradually eliminated with increasingly intelligent path management tools.Provided by the companies shown in the Ceramic AM Technology Map, FFF currently offers a promising method for producing ceramic prototypes or small series of non-technical ceramic objects.
The pneumatic extrusion process uses air pressure to extrude material in layers, and the printhead mechanism is similar to that used in thermoplastic extrusion processes.Compatible materials include traditional ceramics such as clay and pottery (as well as thermosets and bioprinting materials such as bioinks and hydrogels).In ceramic additive manufacturing, pneumatic extrusion may be more suitable for art and design applications.The process uses pressure typically provided by a compressed air system or syringe to extrude and selectively deposit the ceramic slurry.This paste, similar to the paste used in handmade ceramics, is a mixture of ceramic powder and water in a proportion that is liquid enough to extrude but thick enough to layer in layers without collapsing.Pneumatic extrusion systems can be stand-alone printers built specifically for ceramics (Cartesian or, more commonly, triangular), or as add-on kits to standard thermoplastic extrusion 3D printers.
Material jetting can be considered the most technologically advanced type of 3D printing and the one that enables the most voxel-level control.Material ejection systems use inkjet heads to eject material through thousands or even millions of digitally controlled nozzles.In some cases, the material jetting process is combined with extrusion or binder jetting.The only representative of binder jetting technology in ceramics is the Israeli company XJet, as shown in the 3dpbm map of ceramic additive manufacturing technology.The XJet NanoParticle jetting process utilizes metal nanoparticles mixed with water to create a solution that can act as both a solid and a liquid.The solution is sprayed onto a heated platform and solidifies as the water evaporates, forming the green part.The technology is also able to use different water-soluble materials as supports, enabling the production of complex geometries.The green part is then sintered in a furnace in a post-processing process, resulting in a high density part.
This market study by 3dpbm Research provides an in-depth analysis and forecast of ceramic additives…
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Post time: Mar-18-2022