The development of a framework to produce additively manufactured, low-cost aluminum via material extrusion process

In the last half century, 3D printing – or additive manufacturing (AM) – has emerged as an efficient and cost-effective method for both large scale and consumer level manufacturing. While technology exists at the professional level for AM of metals, this equipment is cost-prohibitive for the average user, and as such the consumer field is mostly limited to plastics and some plastic-fiber composites. A promising area of study is in plastic-metal composite materials printed using material extrusion (MEX), which are sintered post-printing to remove the plastic binder and yield a solid metal part. One such material, a mixture of polylactic acid (PLA) and aluminum, would prove useful for several reasons. PLA is one of the easiest materials to produce with MEX, making it a good matrix for this composite. As well, aluminum is one of the most widely used metals in industry due to its low cost, high strength to weight ratio, and good corrosion resistance. Being able to additively manufacture parts using this method would avoid many of the limitations associated with traditional manufacturing, produce less waste material, and allow for the average consumer to produce functional and strong parts using readily available technology. However, little research exists on sintering aluminum parts produced with this method, with initial findings suggesting that the equipment and processes needed for this are outside the reach of the average consumer. This research study explores the feasibility of using this method to produce accurate and useable parts, examining the printing parameters to use for most reliable sintering and best post-sinter quality, along with what is needed to achieve successful sintering of printed parts.