Additive Manufacturing (AM)'s applications, for example: 3D-printed spare-parts, require a high dimensional accuracy, where the dimensions of manufactured parts meet the design specifications of tolerances. Different additive manufacturing processes exhibit different dimensional accuracy. The fabrication parameters within the same AM process are affecting the dimensional accuracy. A critical factor that can affect the dimensional accuracy of an AM process is the printing material. With the rapid expansion of AM applications, various printing materials, such as composites and metal alloys, have been developed. Many studies evaluated the dimensional accuracy of plastic parts produced via the Fused Filament Fabrication (FFF) process. To our knowledge, there is a lack of understanding of the dimensional accuracy of metal parts produced via FFF in the literature. Hence, this work investigates the dimensional accuracy of metal printing materials in FFF technologies by performing experiments and analyses.We designed experiments to evaluate the dimensional accuracy of additively manufactured metal parts produced by FFF processes. We designed a new testing-structure incorporating multiple features in one build, such as: diameters, linear dimensions, extrusions, grooves, and depth. The testing-structure part was designed to evaluate multiple geometrical shapes that are commonly found in functional parts. Two different metal materials of 17-4 PH stainless steel and copper were used to manufacture the testing-structure parts. We will use a commercial Metalx 3D printer to manufacture the metal parts. We will also compare the dimensional accuracy of metal parts against the plastic parts from Onyx material fabricated using a commercial X7 3D printer. For each material, three identical specimens will be manufactured to test their dimensional accuracy and the consistency of the manufacturing process.The manufactured specimens will be scanned using a Hexagon arm 3D laser scanner to precisely measure the dimensions and capture the geometry's details. The scanned results will be processed and compared to the original CAD model using Geometric Control X software. Three-dimensional analysis including cross-sectional drawings will be used as a reference to measure the accuracy of the width, height, and cylindrical diameters.We hypothesize that FFF metal parts will have worse dimensional accuracy than FFF plastic parts. The 3D printing of plastic parts via the FFF process has only one step, which is printing. However, in metal 3D printing via the FFF process, the parts need to go through three steps: washing, drying, and sintering. We argued that the more the process steps involved, the more chance of error during processes, decreasing the quality of dimensional accuracy. Thus, we expect that parts printed using Onyx material will have better dimensional accuracy compared to the parts printed in 17-4 PH stainless steel and copper metal materials.

Evaluation of Dimensional Accuracy of Additively Manufactured Metal Parts in Fused Filament Fabrication Process

Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2021/volume/85543

ASME 2021 International Mechanical Engineering Congress and Exposition (IMECE2021)

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.