Flash Sintered Additive Manufacturing

Physical Sciences : Mechanical

Available for licensing

Inventors

  • Joseph Beaman, Jr., Ph.D. , Mechanical Engineering
  • Desiderio Kovar, Ph.D. , Mechanical Engineering
  • David Bourell, Ph.D. , Mechanical Engineering
  • Deborah Hagen , Advanced Manufacturing Center

Background/unmet need

Ceramics are an industrially and commercially important material created via additive manufacturing (AM). According to Grand View Research, the global technical ceramics market will be worth $134.58 billion by 2024. Demand is expected to continuously increase due to the material’s cost effectiveness, lifespan, and benefits such as biodegradability, durability, and high tensile strength. Such properties are highly desirable for a number of applications and industries, such as in the growing medical and automotive sectors.

Traditional AM sintering methods in the ceramics industry require several hours of processing. The risk for fractures caused by AM greatly inhibits production of small parts, limiting the types of ceramics that can be efficiently produced. Additionally, organic binders are a necessary component of the traditional sintering process that enable ceramics to retain their unique physio-chemical properties. Currently, there are no reliable methods for AM of ceramics without the use of organic binders, which adds to resource costs and processing time.

Flash sintering, also known as spark plasma sintering, has been considered as a possible solution to the inefficiency of AM but remains relatively unexplored. Flash sintering can allow for many types of ceramic powders to be sintered to full density in only a few seconds. The implementation of a flash sintering method that can reduce resource costs, decrease processing time, improve production quality, and apply to a variety of ceramic products has the potential to completely transform the AM process in the ceramics industry.

Invention Description

Researchers at The University of Texas at Austin have developed an approach to additive manufacturing through flash sintering tests on alumina, one of the most commercially-relevant ceramic materials with applications in additive manufacturing. They demonstrated that with the proper temperature and electric field, the temperature and time required to sinter various ceramic materials is significantly lowered. For example, a ceramic product can be flash sintered to 60% density within seconds, a dramatic improvement to the traditional process requiring several hours, that is strong enough to be handled and easily brought to near theoretical density in a furnace. Tests showed that this two-step process allows the ceramics to retain fine features as well.

Flash sintering can be combined with selective laser sintering to increase sintering speed, improve the handling of small ceramic products, and diversify the variety of materials that can be effectively manufactured. The combination of flash sintering and selective laser sintering can potentially allow for binder-free additive manufacturing of ceramics, lowering resource costs and eliminating the time-consuming removal process of organic binders from the ceramic. Flash sintering can potentially improve the production speed and handling of any material at the microscopic level, in which the electric field acts as a thermal process that controls the mechanical properties of the material. When applied at the systematic level, flash sintering can greatly ease the fabrication of small ceramic parts and increase the use of additive manufacturing for ceramics.

Benefits/Advantages

  • Significantly decreases sintering time from hours to seconds
  • Lowers temperature needed for sintering
  • Lowers resource costs (e.g. eliminates organic binders)
  • Allows ceramics to retain fine features during sintering process
  • Increases variety of ceramics that can be produced by additive manufacturing
  • Allows for fabrication of small ceramic parts
  • Minimizes risk of ceramic fracture

Features

  • Simple two-step sintering process
  • Produces densified material in a matter of seconds
  • Allows for efficient additive manufacturing of ceramics
  • Can be coupled with selective laser sintering
  • Application to a wide variety of ceramic products
  • Improved handling of small ceramic parts
  • Potentially allows for binder-free additive manufacturing
  • Potentially allows for customization of material mechanical properties
  • Potentially applicable to any material at the microscopic level

Market potential/applications

Persistence Market Research reports that the global additive manufacturing market value is expected to expand at a compound annual growth rate (CAGR) around 18% to 22% during the period 2015-2025. Additionally, an Allied Market Research’s report on 3D printing predicts that selective laser sintering and fused deposition modeling will be the most demanded additive manufacturing techniques in the future as markets grow and technology becomes cheaper. The increasing demand for additive manufacturing and 3D printing in automotive, manufacturing, and healthcare industries is attributed to the design of complex parts and finished goods. Enhanced additive manufacturing processes are ideal for fabricating these intricate products in that it is applicable to a variety of materials, such as plastics, metal alloys, rubber, and ceramics.

Development Stage

Proof of concept

IP Status

  • 1 PCT patent application filed
  • 2 U.S. patents application filed