Technologist, Consultant, and Subject Matter Expert, Ultra-High-Temp Materials and Heat Shields. Available as a Board Advisor and Expert Witness. US Citizen.
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GREEN MANUFACTURING OF ADVANCED MATERIALS A manufactured product requires both energy and raw materials. This is a fact. The real question is “How much energy is needed and how much raw materials are required?” From that perspective no manufactured product is 100% green, but they certainly can be much greener! Three technologies have evolved that can make the manufacturing of high temperature and ultra-high-temperature (UHT) materials much more energy efficient and raw materials efficient. The three technologies are 3D Printing (Additive Manufacturing), Microwave Sintering, and Field Assisted Sintering Technology (FAST). 3D Printing (Additive Manufacturing): 3D printing is great for high temperature alloys for combustion, missile propulsion, and hypersonics. This technology has progressed tremendously in recent years. ProtoLabs has recently demonstrated a very intricate dual wall combustor, as one example. Without 3D printing, these types of complex components would have required numerous high tolerance machined parts to assemble and wasted up to 90 percent of the material. Dozens of companies worldwide have demonstrated dramatic progress in 3D printed metallic alloys, ceramics, and cermets (ceramic-metal composites). Continuous fiber reinforced composites, however, remain an elusive challenge. That includes, especially, ceramic matrix composites (CMCs). Microwave Sintering: Microwave sintering started in the 1980s and has since gained traction in industry. There are two types of microwave sintering, direct and indirect. In direct microwave sintering, the microwaves couple directly with the material being sintered. That works well for materials that are microwave susceptors. Many materials are not, however, so indirect microwave sintering uses highly efficient microwave susceptors as “heating elements” to absorb the microwave energy and convert it efficiently to heat. Both approaches are very energy efficient when compared to traditional furnaces used in processing materials, saving as much as 75 percent in energy costs. Field Assisted Sintering Technology (FAST): FAST, very similar to Spark Plasma Sintering (SPS), is a highly efficient means of densifying extremely challenging UHT materials in a very short period of time using relatively little energy. Unlike traditional hot-pressing and hot isostatic pressing (HIP), FAST uses about 70 percent less power and cycle times are much shorter. With proper tooling, it can also be near-net-shape to minimize material waste and require either no post machining or very minimal machining. All three of these technologies advance green manufacturing and sustainability.