Utjecaj kutnoga kanalnoga istiskivanja na tvrdoću kompozita s matricom od Al-legure ojačanoga česticama lebdećega pepela

master's thesis

• Title (english): Influence of ECAP on the hardness of composite based on Al alloy reinforced with fly ash particle
• Author: Edin Prljača
• Mentor: Vera Rede (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2025-03-27, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

U ovom diplomskom radu istražen je utjecaj kutnoga kanalnoga istiskivanja na mikrostrukturu
i mikrotvrdoću kompozita s matricom od aluminijske legure A356.0 ojačane sa 6 % čestica
lebdećega pepela. Kompozit je dobiven postupkom lijevanja uz miješanje u poluskrućenom
stanju, a nakon toga triput istisnut kroz kutni kanal. Mikrostruktura aluminijske matrice
kompozita u lijevanom stanju sastoji se od α-Al kristala mješanaca sferoidnog oblika i silicija
izlučenog u obliku štapića. U ovom stanju čestice lebdećeg pepela nisu ravnomjerno
raspoređene u matrici. Postupak kutnoga kanalnoga istiskivanja deformira i usitnjava
mikrostrukturu kompozita, poboljšava distribuciju čestica lebdećeg pepela te usitnjava štapiće
silicija. Navedene mikrostrukturne promjene utječu na povećanje mikrotvrdoće i čvrstoće
kompozita. Mikrotvrdoća raste nakon svakog novog istiskivanja za bilo koje primijenjeno
opterećenje (HV0,02, HV0,05, HV0,1 i HV0,2). Najviši prirast mikrotvrdoće zabilježen je
nakon prvog prolaza za mikrotvrdoću HV0,2.

Abstract (english)

This thesis investigates the effect of equal channel angular extrusion on the microstructure and
microhardness of a composite with an aluminum alloy A356.0 matrix reinforced with 6% fly
ash particles. The composite was obtained by a compo casting process and then extruded three
times through an angular channel. The microstructure of the aluminum matrix of the composite
in the as-cast state consists of α-Al crystals of spheroidal shape and needle like silicon. In this
state, the fly ash particles are not uniformly distributed in the matrix. The equal channel angular
extrusion process deforms the composite microstructure, reduces the grain size, improves the
distribution of fly ash particles, and fragments the needle like silicon. These microstructural
changes affect the increase in the microhardness and strength of the composite. The
microhardness increases after each new extrusion for any applied load (HV0.02, HV0.05,
HV0.1 and HV0.2). The highest increase in microhardness was recorded after the first pass for
microhardness HV0.2.

• Keywords: kutno kanalno istiskivanje; kompozit; lebdeći pepeo; mikrotvrdoća
• Keywords (english): equal channel angular extrusion; composite; fly ash; microhardness
• Language: croatian
• URN:NBN: urn:nbn:hr:235:741400
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka strojarstva (magistar/magistra inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2025-03-26 17:15:10