Abrazijska otpornost navara od aluminijske bronce

undergraduate thesis

• Title (english): Abrasion resistance of the aluminum bronze overlay
• Author: Josipa Jonjić
• Mentor: Vera Rede (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2023-03-02, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

U radu je provedena usporedba otpornosti na abrazijsko trošenje navara od aluminijske bronce
oznake CuAl8Ni2Fe2Mn2, na osnovnom materijalu oznake CuAl10Fe5Ni5. Analizirana je
mikrostruktura te izmjerena mikrotvrdoća HV0,2 na oba materijala.
U teorijskom dijelu rada opisana je povijest bakra i njegovih legura, njihova podjela i specifična
svojstva, a posebno je opisana aluminijska bronca i područje njezine primjene.
Analiza mikrostrukture pokazala je da se mikrostruktura osnovnog materijala sastoji od kristala
mješanaca i intermetalnog spoja precipitiranog u različitim oblicima. U mikrostrukturi zone
utjecaja topline udio intermetalnih spojeva je viši nego u osnovnom materijalu. Navareni sloj
ima tipičnu ljevačku, dendritnu mikrostrukturu, a između pojedinih slojeva navara nema razlike
u mikrostrukturi.
Razlika između abrazijske otpornosti osnovnog materijala i metala navara nije velika. Između
gubitka mase pri abraziji i udaljenosti od površine navara postoji izrazito slaba i negativna
linearna korelacija, što znači da se abrazijska otpornost neznatno povećava od površine navara
prema osnovnom materijalu.
Između mikrotvrdoće HV0,2 i udaljenosti od površine navara postoji velika pozitivna linearna
korelacija s vrlo visokim koeficijentom R=0,78. Vrijednosti mikrotvrdoće su u rasponu od
152,5 HV0,2 do 312,3 HV0,2. Najviša mikrotvrdoća izmjerena je u zoni utjecaja topline zbog
više izlučenih tvrdih intermetalnih spojeva, a vrijednosti mikrotvrdoće u osnovnom materijalu
viša je od mikrotvrdoće navara i iznosi 249,3 HV0,2.
Analizom rezultata utvrđena je zadovoljavajuća kvaliteta navara.

Abstract (english)

In the paper, a comparison of the resistance to abrasion wear of welds made of aluminium
bronze marked CuAl8Ni2Fe2Mn2, on the base material marked CuAl10Fe5Ni5, was carried
out. The microstructure was analyzed and the microhardness HV0.2 was measured on both
materials.
In the theoretical part of the paper, the history of copper and its alloys, their division and specific
properties is described and aluminum bronze and its field of application are especially
described.
Microstructure analysis showed that the microstructure of the base material consists of crystals
of mixtures and intermetallic compound precipitated in different forms. In the microstructure
of the heat-affected zone, the proportion of intermetallic compounds is higher than in the base
material. The burn layer has a typical foundry, dendritic microstructure and there is no
difference in the microstructure between individual layers of burn.
The difference between the abrasion resistance of the base material and the base metal is not
great. There is an extremely weak and negative linear correlation between the mass loss during
abrasion and the distance from the surface of the weld, which means that the abrasion resistance
slightly increases from the surface of the weld to the base material.
There is a large positive linear correlation between microhardness HV0.2 and the distance from
the weld surface with a very high coefficient R=0.78. Microhardness values range from 152.5
HV0.2 to 312.3 HV0.2. The highest microhardness was measured in the heat-affected zone due
to more secreted hard intermetallic compounds and the microhardness value in the base material
is higher than the microhardenss of the weld and amounts to 249.3 HV0.2.
By analyzing the results, the quality of the weld was determined to be satisfactory.

• Keywords: abrazijsko trošenje; aluminijska bronca; navar; mikrostruktura; tvrdoća
• Keywords (english): abrasive wear; aluminum bronze; weld; microstructure; hardenss
• Language: croatian
• URN:NBN: urn:nbn:hr:235:537317
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-03-01 21:21:23