The buzz around the manufacturing world during the past several years has been the commercial introduction of additive manufacturing technologies with the ability to fabricate a wide variety of materials. While additive technologies have been around for quite some time, several limitations have constrained their use to small scale laboratories and research institutions. These limitations included poor surface finish, variations in final properties, and a lack of traceability from raw material to final part.
However, in just the past three years we have seen a rapid increase in adoption of additive process both through increased investments in equipment manufacturers by venture capitalists and acceptance of additively made parts by larger commercial companies such as Boeing and Raytheon. Adoption of this new technology carries with it several benefits including rapid prototyping, increased part complexity, and a reduction in overall waste, and increased implementation is key to ensure the US continues to be a leader in complex manufacturing. However, one aspect of this new revolution that has been slow to adapt are the tools utilized in supply-chain tracking from initial raw material to final product. The raw materials used in additive manufacturing are vastly different than those typically found in traditional manufacturing, and slow adoption of new tools to ensure efficient organization and storage of these materials could limit the exposure of additive parts even as these technologies mature.
Within traditional manufacturing, companies begin with a large piece of material (such as bar or round stock) which is then machined down into its final form. Additive manufacturing replaces this need of stock reduction by building parts layer-by-layer with either very fine metallic powder or small diameter wires. This approach leads to the reduction in overall waste by building a part to near its final shape with just a minimal amount of traditional machining after to achieve the necessary surface finish.
However, the use of these new materials, primarily the fine powder, introduces additional challenges that become increasingly problematic as companies store vast amounts in order to meet production requirements. One of the major issues that has been discussed in detail both in academic papers and industrial newsletters is the inherent flammability and potential explosivity of fine metal powders. These explosive events have been known for some time and led to the formation of several NFPA codes (652 & 654) that worked to set standards for housekeeping and handling. However, even with these standards, the combustibility issue came to light within the additive community back in 2013 at Powderpart a company in Woburn, Massachusetts. This case was not due to a malfunction in the technology itself but rather to unsafe handling procedures, leading to a small explosion harming a single employee. This inherent flammability, due to the high surface-area-to-volume ratio of these powders, also leads to another concern not present in traditional manufacturing--that of a shelf life for these raw materials. Due to the high surface area, these powders, which are typically first processed to reduce surface contaminates and oxides, have properties that can change over time. If these changes are not accounted for during process of the final part, one can end up with variabilities and potential rejects causing a loss in capital. From these two challenges one can see there is a need to reinvent the supply chain tracking and material storage and handling to reduce potential risks and avoid any loss in cost savings.
This is where Solvus Global has turned its attention to in the past year. As we continued to process larger amounts of powder and required the on-site storage of large stocks of raw powder, we realized there had to be a better method of handling and storing these powders. In addition, we realized there was a strong benefit in creating a pedigree for our processed powders that gave the end user the comfort in knowing the exact properties of that batch of powder and not just the general properties of a powder of that type. We have developed a characterization suite able to capture several different varieties of important data, ranging from flowability to compressibility, to help ensure the correct selection of parameters for final fabrication. Instead of generalizing these properties for a specific material, we generate this data for each batch to not only ensure quality but also to provide the end user with traceable data to ensure consistency over time.
This also led us to working closely with fire protection experts to fully understand the everchanging NFPA landscape making sure we were on the cutting edge of powder safety and storage. Luckily, increasing the safety of our powder storage also helps increase the quality control and shelf life of our product. There are many steps within the process that allow for these increases, but the two major impacts are the individual, inert containers we use to store our processed material, and the creation of a smart storage cabinet that can help the user avoid potential combustibility risks while providing them all the inventory tracking they need to ensure their supply chain is always running smoothly. We opted with individual, inert containers, ranging in size from a few pounds to several 10s of pounds, to avoid the degradation of the powders’ properties over time that is typically seen in large bulk drums. These individual containers, to be used for single productions, also avoid segregation of the powder that can be seen in larger containers. This helps to create a more consistent product and helps the end user dial in the parameters necessary for a repeatable manufacturing process.
We are also in the process of finalizing our smart storage cabinet that will provide the end user with an easy-to-use modular system that will ensure simple powder tracking and organization. One can already imagine the logistical nightmare of efficiently storing hundreds of pounds of various metals powders in a method that is easy for machine operators to find the product they need for fabrication. This is made even more challenging when one realizes that certain materials cannot be stored in the same location as other due to potential flammability risks and incompatibilities. Our storage system reduces these logistical problems by tracking the location and amount of each powder within the facility, and the easy-to-use modular system will allow for introduction of new protective cabinets whenever a new, incompatible material is added into the supply chain. As additive manufacturing continues to be widely adopted by the commercial community, this simple Powder-to-Part tracking and efficient organization is going to be paramount in establishing a consistent and reliable final product.
Visit Powders on Demand to purchase metal feedstock powders in varying quantities and materials; create your own custom powder by contacting a member of the POD team.
