Abrasiv nötning av polymerer tillverkade genom 3D-skrivning
ÅFVolvo CarsVolvoPolymerFDMLancasterTSEAbrasive wearWearMechanical engineeringStrength of materials3D-printing3D-printerPolymerÅFVolvo CarsVolvoPolymerPolymerer3D-skrivning3DAbrasiv nötningAbrasivNötningMaskiningenjörMaskinteknikMaterialTermoplasterTribologiAnisotropiTribometerJämförelseNötningsbeständighetNötningskoefficientHållfasthet
Volvo Cars in Skövde manufacture and assemble Volvo engines. When attaching the ignition coil to all 4-cylinder engines, a special mounting tool is required. This mounting tool is currently manufactured from injection-molded polyoxymethylene (POM), a thermoplastic. It has been noted that the life span of the tool is shortened as a result of abrasive wear that occurs during the attachment process of the ignition coil.An investigation of the possibility of manufacturing the mounting tool with a 3D-printer is undertaken in cooperation with ÅF, a consultant to Volvo Cars. A literature study is first presented to introduce broader knowledge on the subject. The abrasive wear and other material characteristics such as tensile strength, compressive strength and elongation of POM and an alternative material for 3D-printing, Ultem?, an amorphous thermoplastic polyetherimide are discussed. These material characteristics are studied further and considered in tandem with both a theoretical analysis and a wear experiment, based on the pin-on-disc method.It is shown in the theoretical analysis that the wear is approximately six times larger for Ultem? when compared to POM. The wear resistance of Ultem? is highest when wear occurs parallel to the direction of the printed layers. In contrast, the experiment shows that the wear is about three times larger in Ultem? than in POM. The highest tensile strength of Ultem? is also found in the direction of the printed layers. Some issues with the small elongation of the 3D-printed material are presented.It is recommended that ÅF apply the 3D-printing technique with Ultem? only for construction details with complex geometries and where the material elongation will not exceed 5%. It is also recommended that ÅF both support and contribute to this innovative technique in order to develop leading edge competence in the subject.