Što o mikrotvrdoći materijala doznajemo primjenom holografske interferometrije

master's thesis

• Title (english): What can be found about the microhardness of the material by using holografic interferometry
• Author: Maja Stipetić
• Mentor: Nazif Demoli (mentor)
• Granter: University of Zagreb; Faculty of Science; (Department of Physics); Zagreb
• Defense date and country: 2018, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract

Da bi se dobio odgovor na pitanje postavljeno u naslovu ovog diplomskog rada trebalo je prethodno riješiti nekoliko zadataka iz raznih područja: prvo, odabrati materijal te pripremiti uzorke za mjerenja, drugo, ovladati tehnikom mjerenja mikrotvrdoće, treće, ovladati tehnikom holografske interferometrije s mikroskopskim postavom i na kraju dati interpretaciju svih dobivenih rezultata. Odabrani materijal je PLA plastika za koju mnogo mehaničkih svojstava još nije dovoljno istraženo, a jedna je od termoplastika koje se koriste kao materijal za 3D ispis. U novije vrijeme tehnologija 3D ispisivanja doživljava pravi procvat pa je mjerenje svojstava mikrotvrdoće 3D struktura načinjenih od PLA plastike od praktičnog interesa za mnoge primjene. Korišten je 3D pisač Instituta za fiziku, Forcebook UltraPrint 3D. Za mjerenje mikrotvrdoće upotrijebljen je Leitz mikroskop i Vickersova metoda. Istraženo je kako se mijenja Vickersova mikrotvrdoća ispisanih 3D modela u ovisnosti o raznim parametrima ispisa gdje je posebna pažnja posvećena ispunjenosti modela dizajniranih za ovu priliku. Holografska interferometrija općenito daje uvid u topografiju nastalih promjena na nekoj površini. U ovom slučaju, superpozicija dvaju holograma površine uzorka snimljenih prije i nakon indentacije rezultira 3D informacijom u vidu interferencijskih pruga. Interpretacijom dobivenih interferograma dolazi se do odgovora na pitanje postavljeno u naslovu diplomskog rada. Pored tablica s vrijednostima mikrotvrdoće izračunatim Vickersovom metodom, dodatno je ustanovljeno sljedeće: indentacija je plitka s istisnutim materijalom na njenim rubovima i stranama blago savinutim prema središtu utisnute kvadratne piramide. Ova kvalitativna informacija dobivena holografskom interferometrijom lako se može kvantificirati te tako doprinijeti novim saznanjima o proučavanom materijalu.

Abstract (english)

To answer the question posed in the title of this graduate thesis, a number of tasks from different fields had to be resolved: first, select the material and prepare the samples for measurements, second, master the microhardness measurement technique, third, master the holographic interferometry technique with a microscopic setting and finally give an interpretation of the obtained results. The selected material is PLA plastics for which many mechanical properties have not yet been sufficiently explored and is one of the thermoplastics used as a 3D printing material. More recently, 3D printing is experiencing a true blossoming, so measuring the properties of microhardness of a 3D structure made of PLA plastic is of practical interest with many applications. 3D printer available at the Institute of Physics (Forcebook UltraPrint 3D) was used. For microhardness measurement, Leitz microscope and Vickers method were used. How Vickers microhardness of the printed 3D models changes depending on the various print parameters was explored, with a special attention on the infill of models designed for this occasion. Holographic interferometry generally provides an insight into the topography of changes on a surface. In this case, the superposition of the two holograms of the sample surface recorded before and after the indentation results in 3D information in the form of interference lines. By interpreting interferograms, the answer to the question posed in the title of graduate thesis was achieved. In addition to the tables with microhardness values calculated by Vickers method, the following is further established: the indentation is shallow with the piled up material on its edges and sides slightly bent towards the center of the squared pyramid. This qualitative information obtained by holographic interferometry can easily be quantified and thus contribute to new knowledge of the studied material.

• Keywords: tehnologija 3D ispisivanja; termoplastika; PLA plastika; Vickersova mikrotvrdoća; holografska interferometrija
• Keywords (english): 3D printing technology; thermoplastic; PLA plastic; Vickers microhardness; holographic interferometry
• Language: croatian
• URN:NBN: urn:nbn:hr:217:444142
• Study programme: Title: Physics; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra fizike (magistar/magistra fizike)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2018-08-28 11:02:27