2024 ASEE Annual Conference & Exposition

There are many factors to consider when choosing the best manufacturing process and material. This paper reviews how strength, hardness, and surface finish were tested for three-dimensional (3D) printing. Engineering students are taught how to find, measure, and calculate compressive strength and hardness. Students also learn the importance of each of these factors and what can lead to defects. Many studies tend to focus on the properties of just a singular material, but it is important that students explore all types of materials and manufacturing processes they could end up working with. Polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), and carbon fiber (CF) are used for 3D printing. Mechanical properties like compressive strength, hardness, and surface roughness were measured to investigate the resulting products from additive manufacturing. To test each material, different infill ratios (30%, 50%, 70%) and patterns (linear, triangular, honeycomb) will be printed resulting in 27 different specimens for comparison. Hardness is a measure of the resistance a material has to deformation in the form or indentation, a shore durometer was used to test the hardness of each material. Compressive strength is the resistance to deformation under constant compressive force, and universal materials testing equipment is a great teaching aid that can help measure various mechanical properties, a compression force can be applied to each specimen while data is recorded and graphed. Surface finish is an important quality that can affect dimension accuracy and lead to defects from uneven force distribution, precision surface roughness gauges contain a fine probe to measure the quality of the surface. After concluding each test, it was found that carbon fiber with 70% linear infill performed the best for strength and hardness. ABS material produced the smoothest surface. Educators may find it valuable to invest in 3D printing material that will better demonstrate these mechanical properties that are often desired in industry. If engineering students understand which combination of material and infill ratio can produce which mechanical properties, they can compare and decide that production could be transferred to 3D printing while maintaining the same mechanical properties required for the part.