A new technology developed by Penn State researchers, called Cold Sintering Process (CSP), has opened a window on the ability to combine incompatible materials, such as ceramics and plastics, into new, useful compound materials, and to lower the energy cost of many types of manufacturing.
Ceramics is the oldest known man-made material, dating back tens of thousands of years. Throughout that time most all ceramics have been made by heating them to high temperatures, either by firing in kilns or sintering ceramic powders in furnaces, both of which require large amounts of energy.
“In this day and age, when we have to be incredibly conscious of the CO2 budget, the energy budget, rethinking many of our manufacturing processes, including ceramics, becomes absolutely vital,” said Clive Randall, professor of materials science and engineering at Penn State who developed the process with his team. “Not only is it a low temperature process (room temperature up to 200 degrees Celsius), but we are also densifying some materials to over 95 percent of their theoretical density in 15 minutes. We can now make a ceramic faster than you can bake a pizza, and at lower temperatures.”
In a recent article in the journal Advanced Functional Materials, Randall and his coauthors describe the co-sintering of ceramic and thermoplastic polymer composites using CSP. Three types of polymer were selected to complement the properties of three types of ceramics, a microwave dielectric, an electrolyte and a semiconductor, in order to highlight the diversity of applicable materials. These composite materials demonstrate new possibilities for dielectric property design, and both ionic and electronic electrical conductivity design. These composites can be sintered to high density at 120 degrees C in a time frame of 15 to 60 minutes.
Just add water
According to the researchers, the process involves wetting ceramic powder with a few drops of water or acid solution. The solid surfaces of the particles decompose and partially dissolve in the water to produce a liquid phase at particle-particle interfaces. Adding temperature and pressure causes the water to flow and the solid particles to rearrange in an initial densification process. Then in a second process, clusters of atoms or ions move away from where the particles are in contact, which aids diffusion, which then minimizes surface free energy, allowing the particles to pack tightly together. The key is knowing the exact combination of moisture, pressure, heat and time required to capture the reaction rates so the material fully crystallizes and gets to very high density.
“I see cold sintering process as a continuum of different challenges,” Randall said. “In some systems, it’s so easy you don’t need pressure. In others you do. In some you need to use nanoparticles. In others, you can get away with a mixture of nanoparticles and larger particles. It really all depends on the systems and chemistries you are talking about.”
The Penn State team has begun building a library of the precise techniques required to use CSP on various materials systems, with 50 processes verified to-date. These include ceramic-ceramic composites, ceramic-nanoparticle composites, ceramic-metals, as well as the ceramic-polymers discussed in this paper.
Other areas that are now open to exploration by CSP include architectural materials, such as ceramic bricks, thermal insulation, biomedical implants and many types of electronic components.
“My hope is that a lot of the manufacturing processes that already exist will be able to use this process, and we can learn from polymer manufacturing practices,” Randall concluded.
The Latest on: Cold Sintering Process
via Google News
The Latest on: Cold Sintering Process
- Grid Logic’s Multi-Material Powder 3D Printing Systemon July 29, 2022 at 2:32 pm
Grid Logic takes an entirely different approach to powder-based 3D printing. Almost all powder systems use a blade system to deposit each layer of fresh powder, and that mechanism implies use of a ...
- How do heat pumps work? What to know about installation, extreme coldon July 25, 2022 at 2:25 pm
Heat pumps improved performance make them viable for even the coldest of climates. Here's what you should know about heat pumps vs. air conditioners.
- Additive manufacturing takes conformal cooling to new heightson July 20, 2022 at 5:00 pm
Conformal cooling is made possible by using an additive manufacturing process, where metal powder is melted by focused laser beams, layer upon layer. These layers are built up and joined together as a ...
- laser sinteringon July 19, 2022 at 5:00 pm
Selective Laser Sintering 3D printers use a laser on a ... We’ve put his video of the whole process below the break, complete with worrying faults in home-made laser wiring.
- Metal Processing Chemicals Market Overview By Rising Trends And Demands Forecast, 20212030on July 11, 2022 at 2:57 pm
The process of refining and smelting scrap metals ... By Product type (Cleaner and Degreaser, Pre-Paint Conversion Coating, Cold Forming Conversion Coatings, Paint Strippers/Removers, Rust ...
- Overcoming The “Cold Start” Problem in Healthcareon July 11, 2022 at 12:44 pm
Overcoming the cold start problem in healthcare can be incredibly difficult. That said, there are network effects building tactics from Chen’s book and beyond that digital health leaders should keep ...
- Molding the future of thermosets, Part IIon June 15, 2022 at 5:00 pm
Perstorp offers part, process, and tool design services ... Standard hoppers will do. Plenco is helping develop cold-manifold molding to speed cycles and new chemical recipes to facilitate recycling.
- Hot & Cold Isostatic Pressingon March 8, 2022 at 9:30 am
This research CIP is used to shape form powders into a green body, prior to sintering. This model allows the pressing of various shapes, including discs, bars, and tubes, and is therefore a ...
- Field Assisted Sintering Technologyon March 7, 2022 at 9:17 am
Controlled and rapid solid-state sintering process for a wide range of powder and particulate materials. It can consolidate a wide-range of metallic, ceramic, and functional materials. Capability to ...
via Bing News